testbed/astropy__astropy/cextern/cfitsio/lib/eval_f.c

/************************************************************************/
/*                                                                      */
/*                       CFITSIO Lexical Parser                         */
/*                                                                      */
/* This file is one of 3 files containing code which parses an          */
/* arithmetic expression and evaluates it in the context of an input    */
/* FITS file table extension.  The CFITSIO lexical parser is divided    */
/* into the following 3 parts/files: the CFITSIO "front-end",           */
/* eval_f.c, contains the interface between the user/CFITSIO and the    */
/* real core of the parser; the FLEX interpreter, eval_l.c, takes the   */
/* input string and parses it into tokens and identifies the FITS       */
/* information required to evaluate the expression (ie, keywords and    */
/* columns); and, the BISON grammar and evaluation routines, eval_y.c,  */
/* receives the FLEX output and determines and performs the actual      */
/* operations.  The files eval_l.c and eval_y.c are produced from       */
/* running flex and bison on the files eval.l and eval.y, respectively. */
/* (flex and bison are available from any GNU archive: see www.gnu.org) */
/*                                                                      */
/* The grammar rules, rather than evaluating the expression in situ,    */
/* builds a tree, or Nodal, structure mapping out the order of          */
/* operations and expression dependencies.  This "compilation" process  */
/* allows for much faster processing of multiple rows.  This technique  */
/* was developed by Uwe Lammers of the XMM Science Analysis System,     */
/* although the CFITSIO implementation is entirely code original.       */
/*                                                                      */
/*                                                                      */
/* Modification History:                                                */
/*                                                                      */
/*   Kent Blackburn      c1992  Original parser code developed for the  */
/*                              FTOOLS software package, in particular, */
/*                              the fselect task.                       */
/*   Kent Blackburn      c1995  BIT column support added                */
/*   Peter D Wilson   Feb 1998  Vector column support added             */
/*   Peter D Wilson   May 1998  Ported to CFITSIO library.  User        */
/*                              interface routines written, in essence  */
/*                              making fselect, fcalc, and maketime     */
/*                              capabilities available to all tools     */
/*                              via single function calls.              */
/*   Peter D Wilson   Jun 1998  Major rewrite of parser core, so as to  */
/*                              create a run-time evaluation tree,      */
/*                              inspired by the work of Uwe Lammers,    */
/*                              resulting in a speed increase of        */
/*                              10-100 times.                           */
/*   Peter D Wilson   Jul 1998  gtifilter(a,b,c,d) function added       */
/*   Peter D Wilson   Aug 1998  regfilter(a,b,c,d) function added       */
/*   Peter D Wilson   Jul 1999  Make parser fitsfile-independent,       */
/*                              allowing a purely vector-based usage    */
/*   Peter D Wilson   Aug 1999  Add row-offset capability               */
/*   Peter D Wilson   Sep 1999  Add row-range capability to ffcalc_rng  */
/*                                                                      */
/************************************************************************/

#include <limits.h>
#include <ctype.h>
#include "eval_defs.h"
#include "region.h"

typedef struct {
     int  datatype;   /* Data type to cast parse results into for user       */
     void *dataPtr;   /* Pointer to array of results, NULL if to use iterCol */
     void *nullPtr;   /* Pointer to nulval, use zero if NULL                 */
     long maxRows;    /* Max No. of rows to process, -1=all, 0=1 iteration   */
     int  anyNull;    /* Flag indicating at least 1 undef value encountered  */
} parseInfo;

/*  Internal routines needed to allow the evaluator to operate on FITS data  */

static void Setup_DataArrays( int nCols, iteratorCol *cols,
                              long fRow, long nRows );
static int  find_column( char *colName, void *itslval );
static int  find_keywd ( char *key,     void *itslval );
static int  allocateCol( int nCol, int *status );
static int  load_column( int varNum, long fRow, long nRows,
                         void *data, char *undef );

static int DEBUG_PIXFILTER;

#define FREE(x) { if (x) free(x); else printf("invalid free(" #x ") at %s:%d\n", __FILE__, __LINE__); }

/*---------------------------------------------------------------------------*/
int fffrow( fitsfile *fptr,         /* I - Input FITS file                   */
            char     *expr,         /* I - Boolean expression                */
            long     firstrow,      /* I - First row of table to eval        */
            long     nrows,         /* I - Number of rows to evaluate        */
            long     *n_good_rows,  /* O - Number of rows eval to True       */
            char     *row_status,   /* O - Array of boolean results          */
            int      *status )      /* O - Error status                      */
/*                                                                           */
/* Evaluate a boolean expression using the indicated rows, returning an      */
/* array of flags indicating which rows evaluated to TRUE/FALSE              */
/*---------------------------------------------------------------------------*/
{
   parseInfo Info;
   int naxis, constant;
   long nelem, naxes[MAXDIMS], elem;
   char result;

   if( *status ) return( *status );

   FFLOCK;
   if( ffiprs( fptr, 0, expr, MAXDIMS, &Info.datatype, &nelem, &naxis,
               naxes, status ) ) {
      ffcprs();
      FFUNLOCK;
      return( *status );
   }
   if( nelem<0 ) {
      constant = 1;
      nelem = -nelem;
   } else
      constant = 0;

   if( Info.datatype!=TLOGICAL || nelem!=1 ) {
      ffcprs();
      ffpmsg("Expression does not evaluate to a logical scalar.");
      FFUNLOCK;
      return( *status = PARSE_BAD_TYPE );
   }

   if( constant ) { /* No need to call parser... have result from ffiprs */
      result = gParse.Nodes[gParse.resultNode].value.data.log;
      *n_good_rows = nrows;
      for( elem=0; elem<nrows; elem++ )
         row_status[elem] = result;
   } else {
      firstrow     = (firstrow>1 ? firstrow : 1);
      Info.dataPtr = row_status;
      Info.nullPtr = NULL;
      Info.maxRows = nrows;

      if( ffiter( gParse.nCols, gParse.colData, firstrow-1, 0,
                  parse_data, (void*)&Info, status ) == -1 )
         *status = 0;  /* -1 indicates exitted without error before end... OK */

      if( *status ) {

         /***********************/
         /* Error... Do nothing */
         /***********************/

      } else {

         /***********************************/
         /* Count number of good rows found */
         /***********************************/

         *n_good_rows = 0L;
         for( elem=0; elem<Info.maxRows; elem++ ) {
            if( row_status[elem]==1 ) ++*n_good_rows;
         }
      }
   }

   ffcprs();
   FFUNLOCK;
   return(*status);
}

/*--------------------------------------------------------------------------*/
int ffsrow( fitsfile *infptr,   /* I - Input FITS file                      */
            fitsfile *outfptr,  /* I - Output FITS file                     */
            char     *expr,     /* I - Boolean expression                   */
            int      *status )  /* O - Error status                         */
/*                                                                          */
/* Evaluate an expression on all rows of a table.  If the input and output  */
/* files are not the same, copy the TRUE rows to the output file.  If the   */
/* files are the same, delete the FALSE rows (preserve the TRUE rows).      */
/* Can copy rows between extensions of the same file, *BUT* if output       */
/* extension is before the input extension, the second extension *MUST* be  */
/* opened using ffreopen, so that CFITSIO can handle changing file lengths. */
/*--------------------------------------------------------------------------*/
{
   parseInfo Info;
   int naxis, constant;
   long nelem, rdlen, naxes[MAXDIMS], maxrows, nbuff, nGood, inloc, outloc;
   LONGLONG ntodo, inbyteloc, outbyteloc, hsize;
   long freespace;
   unsigned char *buffer, result;
   struct {
      LONGLONG rowLength, numRows, heapSize;
      LONGLONG dataStart, heapStart;
   } inExt, outExt;

   if( *status ) return( *status );

   FFLOCK;
   if( ffiprs( infptr, 0, expr, MAXDIMS, &Info.datatype, &nelem, &naxis,
               naxes, status ) ) {
      ffcprs();
      FFUNLOCK;
      return( *status );
   }

   if( nelem<0 ) {
      constant = 1;
      nelem = -nelem;
   } else
      constant = 0;

   /**********************************************************************/
   /* Make sure expression evaluates to the right type... logical scalar */
   /**********************************************************************/

   if( Info.datatype!=TLOGICAL || nelem!=1 ) {
      ffcprs();
      ffpmsg("Expression does not evaluate to a logical scalar.");
      FFUNLOCK;
      return( *status = PARSE_BAD_TYPE );
   }

   /***********************************************************/
   /*  Extract various table information from each extension  */
   /***********************************************************/

   if( infptr->HDUposition != (infptr->Fptr)->curhdu )
      ffmahd( infptr, (infptr->HDUposition) + 1, NULL, status );
   if( *status ) {
      ffcprs();
      FFUNLOCK;
      return( *status );
   }
   inExt.rowLength = (long) (infptr->Fptr)->rowlength;
   inExt.numRows   = (infptr->Fptr)->numrows;
   inExt.heapSize  = (infptr->Fptr)->heapsize;
   if( inExt.numRows == 0 ) { /* Nothing to copy */
      ffcprs();
      FFUNLOCK;
      return( *status );
   }

   if( outfptr->HDUposition != (outfptr->Fptr)->curhdu )
      ffmahd( outfptr, (outfptr->HDUposition) + 1, NULL, status );
   if( (outfptr->Fptr)->datastart < 0 )
      ffrdef( outfptr, status );
   if( *status ) {
      ffcprs();
      FFUNLOCK;
      return( *status );
   }
   outExt.rowLength = (long) (outfptr->Fptr)->rowlength;
   outExt.numRows   = (outfptr->Fptr)->numrows;
   if( !outExt.numRows )
      (outfptr->Fptr)->heapsize = 0L;
   outExt.heapSize  = (outfptr->Fptr)->heapsize;

   if( inExt.rowLength != outExt.rowLength ) {
      ffpmsg("Output table has different row length from input");
      ffcprs();
      FFUNLOCK;
      return( *status = PARSE_BAD_OUTPUT );
   }

   /***********************************/
   /*  Fill out Info data for parser  */
   /***********************************/

   Info.dataPtr = (char *)malloc( (size_t) ((inExt.numRows + 1) * sizeof(char)) );
   Info.nullPtr = NULL;
   Info.maxRows = (long) inExt.numRows;
   if( !Info.dataPtr ) {
      ffpmsg("Unable to allocate memory for row selection");
      ffcprs();
      FFUNLOCK;
      return( *status = MEMORY_ALLOCATION );
   }
   
   /* make sure array is zero terminated */
   ((char*)Info.dataPtr)[inExt.numRows] = 0;

   if( constant ) { /*  Set all rows to the same value from constant result  */

      result = gParse.Nodes[gParse.resultNode].value.data.log;
      for( ntodo = 0; ntodo<inExt.numRows; ntodo++ )
         ((char*)Info.dataPtr)[ntodo] = result;
      nGood = (long) (result ? inExt.numRows : 0);

   } else {

      ffiter( gParse.nCols, gParse.colData, 0L, 0L,
              parse_data, (void*)&Info, status );

      nGood = 0;
      for( ntodo = 0; ntodo<inExt.numRows; ntodo++ )
         if( ((char*)Info.dataPtr)[ntodo] ) nGood++;
   }

   if( *status ) {
      /* Error... Do nothing */
   } else {
      rdlen  = (long) inExt.rowLength;
      buffer = (unsigned char *)malloc(maxvalue(500000,rdlen) * sizeof(char) );
      if( buffer==NULL ) {
         ffcprs();
         FFUNLOCK;
         return( *status=MEMORY_ALLOCATION );
      }
      maxrows = maxvalue( (500000L/rdlen), 1);
      nbuff = 0;
      inloc = 1;
      if( infptr==outfptr ) { /* Skip initial good rows if input==output file */
         while( ((char*)Info.dataPtr)[inloc-1] ) inloc++;
         outloc = inloc;
      } else {
         outloc = (long) (outExt.numRows + 1);
         if (outloc > 1) 
            ffirow( outfptr, outExt.numRows, nGood, status );
      }

      do {
         if( ((char*)Info.dataPtr)[inloc-1] ) {
            ffgtbb( infptr, inloc, 1L, rdlen, buffer+rdlen*nbuff, status );
            nbuff++;
            if( nbuff==maxrows ) {
               ffptbb( outfptr, outloc, 1L, rdlen*nbuff, buffer,  status );
               outloc += nbuff;
               nbuff = 0;
            }
         }
         inloc++;
      } while( !*status && inloc<=inExt.numRows );

      if( nbuff ) {
         ffptbb( outfptr, outloc, 1L, rdlen*nbuff, buffer,  status );
         outloc += nbuff;
      }

      if( infptr==outfptr ) {

         if( outloc<=inExt.numRows )
            ffdrow( infptr, outloc, inExt.numRows-outloc+1, status );

      } else if( inExt.heapSize && nGood ) {

         /* Copy heap, if it exists and at least one row copied */

         /********************************************************/
         /*  Get location information from the output extension  */
         /********************************************************/

         if( outfptr->HDUposition != (outfptr->Fptr)->curhdu )
            ffmahd( outfptr, (outfptr->HDUposition) + 1, NULL, status );
         outExt.dataStart = (outfptr->Fptr)->datastart;
         outExt.heapStart = (outfptr->Fptr)->heapstart;

         /*************************************************/
         /*  Insert more space into outfptr if necessary  */
         /*************************************************/

         hsize     = outExt.heapStart + outExt.heapSize;
         freespace = (long) (( ( (hsize + 2879) / 2880) * 2880) - hsize);
         ntodo     = inExt.heapSize;

         if ( (freespace - ntodo) < 0) {       /* not enough existing space? */
            ntodo = (ntodo - freespace + 2879) / 2880;  /* number of blocks  */
            ffiblk(outfptr, (long) ntodo, 1, status);   /* insert the blocks */
         }
         ffukyj( outfptr, "PCOUNT", inExt.heapSize+outExt.heapSize,
                 NULL, status );

         /*******************************************************/
         /*  Get location information from the input extension  */
         /*******************************************************/

         if( infptr->HDUposition != (infptr->Fptr)->curhdu )
            ffmahd( infptr, (infptr->HDUposition) + 1, NULL, status );
         inExt.dataStart = (infptr->Fptr)->datastart;
         inExt.heapStart = (infptr->Fptr)->heapstart;

         /**********************************/
         /*  Finally copy heap to outfptr  */
         /**********************************/

         ntodo  =  inExt.heapSize;
         inbyteloc  =  inExt.heapStart +  inExt.dataStart;
         outbyteloc = outExt.heapStart + outExt.dataStart + outExt.heapSize;

         while ( ntodo && !*status ) {
            rdlen = (long) minvalue(ntodo,500000);
            ffmbyt( infptr,  inbyteloc,  REPORT_EOF, status );
            ffgbyt( infptr,  rdlen,  buffer,     status );
            ffmbyt( outfptr, outbyteloc, IGNORE_EOF, status );
            ffpbyt( outfptr, rdlen,  buffer,     status );
            inbyteloc  += rdlen;
            outbyteloc += rdlen;
            ntodo  -= rdlen;
         }

         /***********************************************************/
         /*  But must update DES if data is being appended to a     */
         /*  pre-existing heap space.  Edit each new entry in file  */
         /***********************************************************/

         if( outExt.heapSize ) {
            LONGLONG repeat, offset, j;
            int i;
            for( i=1; i<=(outfptr->Fptr)->tfield; i++ ) {
               if( (outfptr->Fptr)->tableptr[i-1].tdatatype<0 ) {
                  for( j=outExt.numRows+1; j<=outExt.numRows+nGood; j++ ) {
                     ffgdesll( outfptr, i, j, &repeat, &offset, status );
                     offset += outExt.heapSize;
                     ffpdes( outfptr, i, j, repeat, offset, status );
                  }
               }
            }
         }

      } /*  End of HEAP copy  */

      FREE(buffer);
   }

   FREE(Info.dataPtr);
   ffcprs();

   ffcmph(outfptr, status);  /* compress heap, deleting any orphaned data */
   FFUNLOCK;
   return(*status);
}

/*---------------------------------------------------------------------------*/
int ffcrow( fitsfile *fptr,      /* I - Input FITS file                      */
            int      datatype,   /* I - Datatype to return results as        */
            char     *expr,      /* I - Arithmetic expression                */
            long     firstrow,   /* I - First row to evaluate                */
            long     nelements,  /* I - Number of elements to return         */
            void     *nulval,    /* I - Ptr to value to use as UNDEF         */
            void     *array,     /* O - Array of results                     */
            int      *anynul,    /* O - Were any UNDEFs encountered?         */
            int      *status )   /* O - Error status                         */
/*                                                                           */
/* Calculate an expression for the indicated rows of a table, returning      */
/* the results, cast as datatype (TSHORT, TDOUBLE, etc), in array.  If       */
/* nulval==NULL, UNDEFs will be zeroed out.  For vector results, the number  */
/* of elements returned may be less than nelements if nelements is not an    */
/* even multiple of the result dimension.  Call fftexp to obtain the         */
/* dimensions of the results.                                                */
/*---------------------------------------------------------------------------*/
{
   parseInfo Info;
   int naxis;
   long nelem1, naxes[MAXDIMS];

   if( *status ) return( *status );

   FFLOCK;
   if( ffiprs( fptr, 0, expr, MAXDIMS, &Info.datatype, &nelem1, &naxis,
               naxes, status ) ) {
      ffcprs();
      FFUNLOCK;
      return( *status );
   }
   if( nelem1<0 ) nelem1 = - nelem1;

   if( nelements<nelem1 ) {
      ffcprs();
      ffpmsg("Array not large enough to hold at least one row of data.");
      FFUNLOCK;
      return( *status = PARSE_LRG_VECTOR );
   }

   firstrow = (firstrow>1 ? firstrow : 1);

   if( datatype ) Info.datatype = datatype;

   Info.dataPtr = array;
   Info.nullPtr = nulval;
   Info.maxRows = nelements / nelem1;
   
   if( ffiter( gParse.nCols, gParse.colData, firstrow-1, 0,
               parse_data, (void*)&Info, status ) == -1 )
      *status=0;  /* -1 indicates exitted without error before end... OK */

   *anynul = Info.anyNull;
   ffcprs();
   FFUNLOCK;
   return( *status );
}

/*--------------------------------------------------------------------------*/
int ffcalc( fitsfile *infptr,   /* I - Input FITS file                      */
            char     *expr,     /* I - Arithmetic expression                */
            fitsfile *outfptr,  /* I - Output fits file                     */
            char     *parName,  /* I - Name of output parameter             */
            char     *parInfo,  /* I - Extra information on parameter       */
            int      *status )  /* O - Error status                         */
/*                                                                          */
/* Evaluate an expression for all rows of a table.  Call ffcalc_rng with    */
/* a row range of 1-MAX.                                                    */
{
   long start=1, end=LONG_MAX;

   return ffcalc_rng( infptr, expr, outfptr, parName, parInfo,
                      1, &start, &end, status );
}

/*--------------------------------------------------------------------------*/
int ffcalc_rng( fitsfile *infptr,   /* I - Input FITS file                  */
                char     *expr,     /* I - Arithmetic expression            */
                fitsfile *outfptr,  /* I - Output fits file                 */
                char     *parName,  /* I - Name of output parameter         */
                char     *parInfo,  /* I - Extra information on parameter   */
                int      nRngs,     /* I - Row range info                   */
                long     *start,    /* I - Row range info                   */
                long     *end,      /* I - Row range info                   */
                int      *status )  /* O - Error status                     */
/*                                                                          */
/* Evaluate an expression using the data in the input FITS file and place   */
/* the results into either a column or keyword in the output fits file,     */
/* depending on the value of parName (keywords normally prefixed with '#')  */
/* and whether the expression evaluates to a constant or a table column.    */
/* The logic is as follows:                                                 */
/*    (1) If a column exists with name, parName, put results there.         */
/*    (2) If parName starts with '#', as in #NAXIS, put result there,       */
/*        with parInfo used as the comment. If expression does not evaluate */
/*        to a constant, flag an error.                                     */
/*    (3) If a keyword exists with name, parName, and expression is a       */
/*        constant, put result there, using parInfo as the new comment.     */
/*    (4) Else, create a new column with name parName and TFORM parInfo.    */
/*        If parInfo is NULL, use a default data type for the column.       */
/*--------------------------------------------------------------------------*/
{
   parseInfo Info;
   int naxis, constant, typecode, newNullKwd=0;
   long nelem, naxes[MAXDIMS], repeat, width;
   int col_cnt, colNo;
   Node *result;
   char card[81], tform[16], nullKwd[9], tdimKwd[9];

   if( *status ) return( *status );

   FFLOCK;
   if( ffiprs( infptr, 0, expr, MAXDIMS, &Info.datatype, &nelem, &naxis,
               naxes, status ) ) {

      ffcprs();
      FFUNLOCK;
      return( *status );
   }
   if( nelem<0 ) {
      constant = 1;
      nelem = -nelem;
   } else
      constant = 0;

   /*  Case (1): If column exists put it there  */

   colNo = 0;
   if( ffgcno( outfptr, CASEINSEN, parName, &colNo, status )==COL_NOT_FOUND ) {

      /*  Output column doesn't exist.  Test for keyword. */

      /* Case (2): Does parName indicate result should be put into keyword */

      *status = 0;
      if( parName[0]=='#' ) {
         if( ! constant ) {
            ffcprs();
            ffpmsg( "Cannot put tabular result into keyword (ffcalc)" );
            FFUNLOCK;
            return( *status = PARSE_BAD_TYPE );
         }
         parName++;  /* Advance past '#' */
	 if ( (fits_strcasecmp(parName,"HISTORY") == 0 || fits_strcasecmp(parName,"COMMENT") == 0) &&
	      Info.datatype != TSTRING ) {
            ffcprs();
            ffpmsg( "HISTORY and COMMENT values must be strings (ffcalc)" );
	    FFUNLOCK;
	    return( *status = PARSE_BAD_TYPE );
	 }

      } else if( constant ) {

         /* Case (3): Does a keyword named parName already exist */

         if( ffgcrd( outfptr, parName, card, status )==KEY_NO_EXIST ) {
            colNo = -1;
         } else if( *status ) {
            ffcprs();
            FFUNLOCK;
            return( *status );
         }

      } else
         colNo = -1;

      if( colNo<0 ) {

         /* Case (4): Create new column */

         *status = 0;
         ffgncl( outfptr, &colNo, status );
         colNo++;
         if( parInfo==NULL || *parInfo=='\0' ) {
            /*  Figure out best default column type  */
            if( gParse.hdutype==BINARY_TBL ) {
               snprintf(tform,15,"%ld",nelem);
               switch( Info.datatype ) {
               case TLOGICAL:  strcat(tform,"L");  break;
               case TLONG:     strcat(tform,"J");  break;
               case TDOUBLE:   strcat(tform,"D");  break;
               case TSTRING:   strcat(tform,"A");  break;
               case TBIT:      strcat(tform,"X");  break;
               case TLONGLONG: strcat(tform,"K");  break;
               }
            } else {
               switch( Info.datatype ) {
               case TLOGICAL:
                  ffcprs();
                  ffpmsg("Cannot create LOGICAL column in ASCII table");
                  FFUNLOCK;
                  return( *status = NOT_BTABLE );
               case TLONG:     strcpy(tform,"I11");     break;
               case TDOUBLE:   strcpy(tform,"D23.15");  break;
               case TSTRING:   
               case TBIT:      snprintf(tform,16,"A%ld",nelem);  break;
               }
            }
            parInfo = tform;
         } else if( !(isdigit((int) *parInfo)) && gParse.hdutype==BINARY_TBL ) {
            if( Info.datatype==TBIT && *parInfo=='B' )
               nelem = (nelem+7)/8;
            snprintf(tform,16,"%ld%s",nelem,parInfo);
            parInfo = tform;
         }
         fficol( outfptr, colNo, parName, parInfo, status );
         if( naxis>1 )
            ffptdm( outfptr, colNo, naxis, naxes, status );

         /*  Setup TNULLn keyword in case NULLs are encountered  */

         ffkeyn("TNULL", colNo, nullKwd, status);
         if( ffgcrd( outfptr, nullKwd, card, status )==KEY_NO_EXIST ) {
            *status = 0;
            if( gParse.hdutype==BINARY_TBL ) {
	       LONGLONG nullVal=0;
               fits_binary_tform( parInfo, &typecode, &repeat, &width, status );
               if( typecode==TBYTE )
                  nullVal = UCHAR_MAX;
               else if( typecode==TSHORT )
                  nullVal = SHRT_MIN;
               else if( typecode==TINT )
                  nullVal = INT_MIN;
               else if( typecode==TLONG )
                  nullVal = LONG_MIN;
               else if( typecode==TLONGLONG )
                  nullVal = LONGLONG_MIN;
		  
               if( nullVal ) {
                  ffpkyj( outfptr, nullKwd, nullVal, "Null value", status );
                  fits_set_btblnull( outfptr, colNo, nullVal, status );
                  newNullKwd = 1;
               }
            } else if( gParse.hdutype==ASCII_TBL ) {
               ffpkys( outfptr, nullKwd, "NULL", "Null value string", status );
               fits_set_atblnull( outfptr, colNo, "NULL", status );
               newNullKwd = 1;
            }
         }

      }

   } else if( *status ) {
      ffcprs();
      FFUNLOCK;
      return( *status );
   } else {

      /********************************************************/
      /*  Check if a TDIM keyword should be written/updated.  */
      /********************************************************/

      ffkeyn("TDIM", colNo, tdimKwd, status);
      ffgcrd( outfptr, tdimKwd, card, status );
      if( *status==0 ) {
         /*  TDIM exists, so update it with result's dimension  */
         ffptdm( outfptr, colNo, naxis, naxes, status );
      } else if( *status==KEY_NO_EXIST ) {
         /*  TDIM does not exist, so clear error stack and     */
         /*  write a TDIM only if result is multi-dimensional  */
         *status = 0;
         ffcmsg();
         if( naxis>1 )
            ffptdm( outfptr, colNo, naxis, naxes, status );
      }
      if( *status ) {
         /*  Either some other error happened in ffgcrd   */
         /*  or one happened in ffptdm                    */
         ffcprs();
         FFUNLOCK;
         return( *status );
      }

   }

   if( colNo>0 ) {

      /*  Output column exists (now)... put results into it  */

      int anyNull = 0;
      int nPerLp, i;
      long totaln;

      ffgkyj(infptr, "NAXIS2", &totaln, 0, status);

      /*************************************/
      /* Create new iterator Output Column */
      /*************************************/

      col_cnt = gParse.nCols;
      if( allocateCol( col_cnt, status ) ) {
         ffcprs();
         FFUNLOCK;
         return( *status );
      }

      fits_iter_set_by_num( gParse.colData+col_cnt, outfptr,
                            colNo, 0, OutputCol );
      gParse.nCols++;

      for( i=0; i<nRngs; i++ ) {
         Info.dataPtr = NULL;
         Info.maxRows = end[i]-start[i]+1;

          /*
            If there is only 1 range, and it includes all the rows,
            and there are 10 or more rows, then set nPerLp = 0 so
            that the iterator function will dynamically choose the
            most efficient number of rows to process in each loop.
            Otherwise, set nPerLp to the number of rows in this range.
         */

         if( (Info.maxRows >= 10) && (nRngs == 1) &&
             (start[0] == 1) && (end[0] == totaln))
              nPerLp = 0;
         else
              nPerLp = Info.maxRows;

         if( ffiter( gParse.nCols, gParse.colData, start[i]-1,
                     nPerLp, parse_data, (void*)&Info, status ) == -1 )
            *status = 0;
         else if( *status ) {
            ffcprs();
            FFUNLOCK;
            return( *status );
         }
         if( Info.anyNull ) anyNull = 1;
      }

      if( newNullKwd && !anyNull ) {
         ffdkey( outfptr, nullKwd, status );
      }

   } else {

      /* Put constant result into keyword */

      result  = gParse.Nodes + gParse.resultNode;
      switch( Info.datatype ) {
      case TDOUBLE:
         ffukyd( outfptr, parName, result->value.data.dbl, 15,
                 parInfo, status );
         break;
      case TLONG:
         ffukyj( outfptr, parName, result->value.data.lng, parInfo, status );
         break;
      case TLOGICAL:
         ffukyl( outfptr, parName, result->value.data.log, parInfo, status );
         break;
      case TBIT:
      case TSTRING:
	 if (fits_strcasecmp(parName,"HISTORY") == 0) {
	   ffphis( outfptr, result->value.data.str, status);
	 } else if (fits_strcasecmp(parName,"COMMENT") == 0) {
	   ffpcom( outfptr, result->value.data.str, status);
	 } else {
	   ffukys( outfptr, parName, result->value.data.str, parInfo, status );
	 }
         break;
      }
   }

   ffcprs();
   FFUNLOCK;
   return( *status );
}

/*--------------------------------------------------------------------------*/
int fftexp( fitsfile *fptr,      /* I - Input FITS file                     */
            char     *expr,      /* I - Arithmetic expression               */
            int      maxdim,     /* I - Max Dimension of naxes              */
            int      *datatype,  /* O - Data type of result                 */
            long     *nelem,     /* O - Vector length of result             */
            int      *naxis,     /* O - # of dimensions of result           */
            long     *naxes,     /* O - Size of each dimension              */
            int      *status )   /* O - Error status                        */
/*                                                                          */
/* Evaluate the given expression and return information on the result.      */
/*--------------------------------------------------------------------------*/
{
   FFLOCK;
   ffiprs( fptr, 0, expr, maxdim, datatype, nelem, naxis, naxes, status );
   ffcprs();
   FFUNLOCK;
   return( *status );
}

/*--------------------------------------------------------------------------*/
int ffiprs( fitsfile *fptr,      /* I - Input FITS file                     */
            int      compressed, /* I - Is FITS file hkunexpanded?          */
            char     *expr,      /* I - Arithmetic expression               */
            int      maxdim,     /* I - Max Dimension of naxes              */
            int      *datatype,  /* O - Data type of result                 */
            long     *nelem,     /* O - Vector length of result             */
            int      *naxis,     /* O - # of dimensions of result           */
            long     *naxes,     /* O - Size of each dimension              */
            int      *status )   /* O - Error status                        */
/*                                                                          */
/* Initialize the parser and determine what type of result the expression   */
/* produces.                                                                */
/*--------------------------------------------------------------------------*/
{
   Node *result;
   int  i,lexpr, tstatus = 0;
   int xaxis, bitpix;
   long xaxes[9];
   static iteratorCol dmyCol;

   if( *status ) return( *status );

   /* make sure all internal structures for this HDU are current */
   if ( ffrdef(fptr, status) ) return(*status);

   /*  Initialize the Parser structure  */

   gParse.def_fptr   = fptr;
   gParse.compressed = compressed;
   gParse.nCols      = 0;
   gParse.colData    = NULL;
   gParse.varData    = NULL;
   gParse.getData    = find_column;
   gParse.loadData   = load_column;
   gParse.Nodes      = NULL;
   gParse.nNodesAlloc= 0;
   gParse.nNodes     = 0;
   gParse.hdutype    = 0;
   gParse.status     = 0;

   fits_get_hdu_type(fptr, &gParse.hdutype, status );

   if (gParse.hdutype == IMAGE_HDU) {

      fits_get_img_param(fptr, 9, &bitpix, &xaxis, xaxes, status);
      if (*status) {
         ffpmsg("ffiprs: unable to get image dimensions");
         return( *status );
      }
      gParse.totalRows = xaxis > 0 ? 1 : 0;
      for (i = 0; i < xaxis; ++i)
         gParse.totalRows *= xaxes[i];
      if (DEBUG_PIXFILTER)
         printf("naxis=%d, gParse.totalRows=%ld\n", xaxis, gParse.totalRows);
   }
   else if( ffgkyj(fptr, "NAXIS2", &gParse.totalRows, 0, &tstatus) )
   {
      /* this might be a 1D or null image with no NAXIS2 keyword */
      gParse.totalRows = 0;
   } 
   

   /*  Copy expression into parser... read from file if necessary  */


   if( expr[0]=='@' ) {
      if( ffimport_file( expr+1, &gParse.expr, status ) ) return( *status );
      lexpr = strlen(gParse.expr);
   } else {
      lexpr = strlen(expr);
      gParse.expr = (char*)malloc( (2+lexpr)*sizeof(char));
      strcpy(gParse.expr,expr);
   }
   strcat(gParse.expr + lexpr,"\n");
   gParse.index    = 0;
   gParse.is_eobuf = 0;

   /*  Parse the expression, building the Nodes and determing  */
   /*  which columns are needed and what data type is returned  */

   ffrestart(NULL);
   if( ffparse() ) {
      return( *status = PARSE_SYNTAX_ERR );
   }
   /*  Check results  */

   *status = gParse.status;
   if( *status ) return(*status);

   if( !gParse.nNodes ) {
      ffpmsg("Blank expression");
      return( *status = PARSE_SYNTAX_ERR );
   }
   if( !gParse.nCols ) {
      dmyCol.fptr = fptr;         /* This allows iterator to know value of */
      gParse.colData = &dmyCol;   /* fptr when no columns are referenced   */
   }

   result = gParse.Nodes + gParse.resultNode;

   *naxis = result->value.naxis;
   *nelem = result->value.nelem;
   for( i=0; i<*naxis && i<maxdim; i++ )
      naxes[i] = result->value.naxes[i];

   switch( result->type ) {
   case BOOLEAN:
      *datatype = TLOGICAL;
      break;
   case LONG:
      *datatype = TLONG;
      break;
   case DOUBLE:
      *datatype = TDOUBLE;
      break;
   case BITSTR:
      *datatype = TBIT;
      break;
   case STRING:
      *datatype = TSTRING;
      break;
   default:
      *datatype = 0;
      ffpmsg("Bad return data type");
      *status = gParse.status = PARSE_BAD_TYPE;
      break;
   }
   gParse.datatype = *datatype;
   FREE(gParse.expr);

   if( result->operation==CONST_OP ) *nelem = - *nelem;
   return(*status);
}

/*--------------------------------------------------------------------------*/
void ffcprs( void )  /*  No parameters                                      */
/*                                                                          */
/* Clear the parser, making it ready to accept a new expression.            */
/*--------------------------------------------------------------------------*/
{
   int col, node, i;

   if( gParse.nCols > 0 ) {
      FREE( gParse.colData  );
      for( col=0; col<gParse.nCols; col++ ) {
         if( gParse.varData[col].undef == NULL ) continue;
         if( gParse.varData[col].type  == BITSTR )
           FREE( ((char**)gParse.varData[col].data)[0] );
         free( gParse.varData[col].undef );
      }
      FREE( gParse.varData );
      gParse.nCols = 0;
   }

   if( gParse.nNodes > 0 ) {
      node = gParse.nNodes;
      while( node-- ) {
         if( gParse.Nodes[node].operation==gtifilt_fct ) {
            i = gParse.Nodes[node].SubNodes[0];
            if (gParse.Nodes[ i ].value.data.ptr)
	        FREE( gParse.Nodes[ i ].value.data.ptr );
         }
         else if( gParse.Nodes[node].operation==regfilt_fct ) {
            i = gParse.Nodes[node].SubNodes[0];
            fits_free_region( (SAORegion *)gParse.Nodes[ i ].value.data.ptr );
         }
      }
      gParse.nNodes = 0;
   }
   if( gParse.Nodes ) free( gParse.Nodes );
   gParse.Nodes = NULL;

   gParse.hdutype = ANY_HDU;
   gParse.pixFilter = 0;
}

/*---------------------------------------------------------------------------*/
int parse_data( long    totalrows,     /* I - Total rows to be processed     */
                long    offset,        /* I - Number of rows skipped at start*/
                long    firstrow,      /* I - First row of this iteration    */
                long    nrows,         /* I - Number of rows in this iter    */
                int      nCols,        /* I - Number of columns in use       */
                iteratorCol *colData,  /* IO- Column information/data        */
                void    *userPtr )     /* I - Data handling instructions     */
/*                                                                           */
/* Iterator work function which calls the parser and copies the results      */
/* into either an OutputCol or a data pointer supplied in the userPtr        */
/* structure.                                                                */
/*---------------------------------------------------------------------------*/
{
    int status, constant=0, anyNullThisTime=0;
    long jj, kk, idx, remain, ntodo;
    Node *result;
    iteratorCol * outcol;

    /* declare variables static to preserve their values between calls */
    static void *Data, *Null;
    static int  datasize;
    static long lastRow, repeat, resDataSize;
    static LONGLONG jnull;
    static parseInfo *userInfo;
    static long zeros[4] = {0,0,0,0};

    if (DEBUG_PIXFILTER)
       printf("parse_data(total=%ld, offset=%ld, first=%ld, rows=%ld, cols=%d)\n",
                totalrows, offset, firstrow, nrows, nCols);
    /*--------------------------------------------------------*/
    /*  Initialization procedures: execute on the first call  */
    /*--------------------------------------------------------*/
    outcol = colData + (nCols - 1);
    if (firstrow == offset+1)
    {
       userInfo = (parseInfo*)userPtr;
       userInfo->anyNull = 0;

       if( userInfo->maxRows>0 )
          userInfo->maxRows = minvalue(totalrows,userInfo->maxRows);
       else if( userInfo->maxRows<0 )
          userInfo->maxRows = totalrows;
       else
          userInfo->maxRows = nrows;

       lastRow = firstrow + userInfo->maxRows - 1;

       if( userInfo->dataPtr==NULL ) {

          if( outcol->iotype == InputCol ) {
             ffpmsg("Output column for parser results not found!");
             return( PARSE_NO_OUTPUT );
          }
          /* Data gets set later */
          Null = outcol->array;
          userInfo->datatype = outcol->datatype;

          /* Check for a TNULL/BLANK keyword for output column/image */

          status = 0;
          jnull = 0;
          if (gParse.hdutype == IMAGE_HDU) {
             if (gParse.pixFilter->blank)
                jnull = (LONGLONG) gParse.pixFilter->blank;
          }
          else {
             ffgknjj( outcol->fptr, "TNULL", outcol->colnum,
                        1, &jnull, (int*)&jj, &status );

             if( status==BAD_INTKEY ) {
                /*  Probably ASCII table with text TNULL keyword  */
                switch( userInfo->datatype ) {
                   case TSHORT:  jnull = (LONGLONG) SHRT_MIN;      break;
                   case TINT:    jnull = (LONGLONG) INT_MIN;       break;
                   case TLONG:   jnull = (LONGLONG) LONG_MIN;      break;
                }
             }
          }
          repeat = outcol->repeat;
/*
          if (DEBUG_PIXFILTER)
            printf("parse_data: using null value %ld\n", jnull);
*/
       } else {

          Data = userInfo->dataPtr;
          Null = (userInfo->nullPtr ? userInfo->nullPtr : zeros);
          repeat = gParse.Nodes[gParse.resultNode].value.nelem;

       }

       /* Determine the size of each element of the returned result */

       switch( userInfo->datatype ) {
       case TBIT:       /*  Fall through to TBYTE  */
       case TLOGICAL:   /*  Fall through to TBYTE  */
       case TBYTE:     datasize = sizeof(char);     break;
       case TSHORT:    datasize = sizeof(short);    break;
       case TINT:      datasize = sizeof(int);      break;
       case TLONG:     datasize = sizeof(long);     break;
       case TLONGLONG: datasize = sizeof(LONGLONG); break;
       case TFLOAT:    datasize = sizeof(float);    break;
       case TDOUBLE:   datasize = sizeof(double);   break;
       case TSTRING:   datasize = sizeof(char*);    break;
       }

       /* Determine the size of each element of the calculated result */
       /*   (only matters for numeric/logical data)                   */

       switch( gParse.Nodes[gParse.resultNode].type ) {
       case BOOLEAN:   resDataSize = sizeof(char);    break;
       case LONG:      resDataSize = sizeof(long);    break;
       case DOUBLE:    resDataSize = sizeof(double);  break;
       }
    }

    /*-------------------------------------------*/
    /*  Main loop: process all the rows of data  */
    /*-------------------------------------------*/

    /*  If writing to output column, set first element to appropriate  */
    /*  null value.  If no NULLs encounter, zero out before returning. */
/*
          if (DEBUG_PIXFILTER)
            printf("parse_data: using null value %ld\n", jnull);
*/

    if( userInfo->dataPtr == NULL ) {
       /* First, reset Data pointer to start of output array */
       Data = (char*) outcol->array + datasize;

       switch( userInfo->datatype ) {
       case TLOGICAL: *(char  *)Null = 'U';             break;
       case TBYTE:    *(char  *)Null = (char )jnull;    break;
       case TSHORT:   *(short *)Null = (short)jnull;    break;
       case TINT:     *(int   *)Null = (int  )jnull;    break;
       case TLONG:    *(long  *)Null = (long )jnull;    break;
       case TLONGLONG: *(LONGLONG  *)Null = (LONGLONG )jnull;    break;
       case TFLOAT:   *(float *)Null = FLOATNULLVALUE;  break;
       case TDOUBLE:  *(double*)Null = DOUBLENULLVALUE; break;
       case TSTRING: (*(char **)Null)[0] = '\1';
                     (*(char **)Null)[1] = '\0';        break;
       }
    }

    /* Alter nrows in case calling routine didn't want to do all rows */

    nrows = minvalue(nrows,lastRow-firstrow+1);

    Setup_DataArrays( nCols, colData, firstrow, nrows );

    /* Parser allocates arrays for each column and calculation it performs. */
    /* Limit number of rows processed during each pass to reduce memory     */
    /* requirements... In most cases, iterator will limit rows to less      */
    /* than 2500 rows per iteration, so this is really only relevant for    */
    /* hk-compressed files which must be decompressed in memory and sent    */
    /* whole to parse_data in a single iteration.                           */

    remain = nrows;
    while( remain ) {
       ntodo = minvalue(remain,2500);
       Evaluate_Parser ( firstrow, ntodo );
       if( gParse.status ) break;

       firstrow += ntodo;
       remain   -= ntodo;

       /*  Copy results into data array  */

       result = gParse.Nodes + gParse.resultNode;
       if( result->operation==CONST_OP ) constant = 1;

       switch( result->type ) {

       case BOOLEAN:
       case LONG:
       case DOUBLE:
          if( constant ) {
             char undef=0;
             for( kk=0; kk<ntodo; kk++ )
                for( jj=0; jj<repeat; jj++ )
                   ffcvtn( gParse.datatype,
                           &(result->value.data),
                           &undef, result->value.nelem /* 1 */,
                           userInfo->datatype, Null,
                           (char*)Data + (kk*repeat+jj)*datasize,
                           &anyNullThisTime, &gParse.status );
          } else {
             if ( repeat == result->value.nelem ) {
                ffcvtn( gParse.datatype,
                        result->value.data.ptr,
                        result->value.undef,
                        result->value.nelem*ntodo,
                        userInfo->datatype, Null, Data,
                        &anyNullThisTime, &gParse.status );
             } else if( result->value.nelem == 1 ) {
                for( kk=0; kk<ntodo; kk++ )
                   for( jj=0; jj<repeat; jj++ ) {
                      ffcvtn( gParse.datatype,
                              (char*)result->value.data.ptr + kk*resDataSize,
                              (char*)result->value.undef + kk,
                              1, userInfo->datatype, Null,
                              (char*)Data + (kk*repeat+jj)*datasize,
                              &anyNullThisTime, &gParse.status );
                   }
             } else {
                int nCopy;
                nCopy = minvalue( repeat, result->value.nelem );
                for( kk=0; kk<ntodo; kk++ ) {
                   ffcvtn( gParse.datatype,
                           (char*)result->value.data.ptr
                                  + kk*result->value.nelem*resDataSize,
                           (char*)result->value.undef
                                  + kk*result->value.nelem,
                           nCopy, userInfo->datatype, Null,
                           (char*)Data + (kk*repeat)*datasize,
                           &anyNullThisTime, &gParse.status );
                   if( nCopy < repeat ) {
                      memset( (char*)Data + (kk*repeat+nCopy)*datasize,
                              0, (repeat-nCopy)*datasize);
                   }
                }

             }
             if( result->operation>0 ) {
                FREE( result->value.data.ptr );
             }
          }
          if( gParse.status==OVERFLOW_ERR ) {
             gParse.status = NUM_OVERFLOW;
             ffpmsg("Numerical overflow while converting expression to necessary datatype");
          }
          break;

       case BITSTR:
          switch( userInfo->datatype ) {
          case TBYTE:
             idx = -1;
             for( kk=0; kk<ntodo; kk++ ) {
                for( jj=0; jj<result->value.nelem; jj++ ) {
                   if( jj%8 == 0 )
                      ((char*)Data)[++idx] = 0;
                   if( constant ) {
                      if( result->value.data.str[jj]=='1' )
                         ((char*)Data)[idx] |= 128>>(jj%8);
                   } else {
                      if( result->value.data.strptr[kk][jj]=='1' )
                         ((char*)Data)[idx] |= 128>>(jj%8);
                   }
                }
             }
             break;
          case TBIT:
          case TLOGICAL:
             if( constant ) {
                for( kk=0; kk<ntodo; kk++ )
                   for( jj=0; jj<result->value.nelem; jj++ ) {
                      ((char*)Data)[ jj+kk*result->value.nelem ] =
                         ( result->value.data.str[jj]=='1' );
                   }
             } else {
                for( kk=0; kk<ntodo; kk++ )
                   for( jj=0; jj<result->value.nelem; jj++ ) {
                      ((char*)Data)[ jj+kk*result->value.nelem ] =
                         ( result->value.data.strptr[kk][jj]=='1' );
                   }
             }
             break; 
          case TSTRING:
             if( constant ) {
                for( jj=0; jj<ntodo; jj++ ) {
                   strcpy( ((char**)Data)[jj], result->value.data.str );
                }
             } else {
                for( jj=0; jj<ntodo; jj++ ) {
                   strcpy( ((char**)Data)[jj], result->value.data.strptr[jj] );
                }
             }
             break;
          default:
             ffpmsg("Cannot convert bit expression to desired type.");
             gParse.status = PARSE_BAD_TYPE;
             break;
          }
          if( result->operation>0 ) {
             FREE( result->value.data.strptr[0] );
             FREE( result->value.data.strptr );
          }
          break;

       case STRING:
          if( userInfo->datatype==TSTRING ) {
             if( constant ) {
                for( jj=0; jj<ntodo; jj++ )
                   strcpy( ((char**)Data)[jj], result->value.data.str );
             } else {
                for( jj=0; jj<ntodo; jj++ )
                   if( result->value.undef[jj] ) {
                      anyNullThisTime = 1;
                      strcpy( ((char**)Data)[jj],
                              *(char **)Null );
                   } else {
                      strcpy( ((char**)Data)[jj],
                              result->value.data.strptr[jj] );
                   }
             }
          } else {
             ffpmsg("Cannot convert string expression to desired type.");
             gParse.status = PARSE_BAD_TYPE;
          }
          if( result->operation>0 ) {
             FREE( result->value.data.strptr[0] );
             FREE( result->value.data.strptr );
          }
          break;
       }

       if( gParse.status ) break;

       /*  Increment Data to point to where the next block should go  */

       if( result->type==BITSTR && userInfo->datatype==TBYTE )
          Data = (char*)Data
                    + datasize * ( (result->value.nelem+7)/8 ) * ntodo;
       else if( result->type==STRING )
          Data = (char*)Data + datasize * ntodo;
       else
          Data = (char*)Data + datasize * ntodo * repeat;
    }

    /* If no NULLs encountered during this pass, set Null value to */
    /* zero to make the writing of the output column data faster   */

    if( anyNullThisTime )
       userInfo->anyNull = 1;
    else if( userInfo->dataPtr == NULL ) {
       if( userInfo->datatype == TSTRING )
          memcpy( *(char **)Null, zeros, 2 );
       else 
          memcpy( Null, zeros, datasize );
    }

    /*-------------------------------------------------------*/
    /*  Clean up procedures:  after processing all the rows  */
    /*-------------------------------------------------------*/

    /*  if the calling routine specified that only a limited number    */
    /*  of rows in the table should be processed, return a value of -1 */
    /*  once all the rows have been done, if no other error occurred.  */

    if (gParse.hdutype != IMAGE_HDU && firstrow - 1 == lastRow) {
           if (!gParse.status && userInfo->maxRows<totalrows) {
                  return (-1);
           }
    }

    return(gParse.status);  /* return successful status */
}

static void Setup_DataArrays( int nCols, iteratorCol *cols,
                              long fRow, long nRows )
    /***********************************************************************/
    /*  Setup the varData array in gParse to contain the fits column data. */
    /*  Then, allocate and initialize the necessary UNDEF arrays for each  */
    /*  column used by the parser.                                         */
    /***********************************************************************/
{
   int     i;
   long    nelem, len, row, idx;
   char  **bitStrs;
   char  **sptr;
   char   *barray;
   long   *iarray;
   double *rarray;
   char msg[80];

   gParse.firstDataRow = fRow;
   gParse.nDataRows    = nRows;

   /*  Resize and fill in UNDEF arrays for each column  */

   for( i=0; i<nCols; i++ ) {

      iteratorCol *icol = cols + i;
      DataInfo *varData = gParse.varData + i;

      if( icol->iotype == OutputCol ) continue;

      nelem  = varData->nelem;
      len    = nelem * nRows;

      switch ( varData->type ) {

      case BITSTR:
      /* No need for UNDEF array, but must make string DATA array */
         len = (nelem+1)*nRows;   /* Count '\0' */
         bitStrs = (char**)varData->data;
         if( bitStrs ) FREE( bitStrs[0] );
         free( bitStrs );
         bitStrs = (char**)malloc( nRows*sizeof(char*) );
         if( bitStrs==NULL ) {
            varData->data = varData->undef = NULL;
            gParse.status = MEMORY_ALLOCATION;
            break;
         }
         bitStrs[0] = (char*)malloc( len*sizeof(char) );
         if( bitStrs[0]==NULL ) {
            free( bitStrs );
            varData->data = varData->undef = NULL;
            gParse.status = MEMORY_ALLOCATION;
            break;
         }

         for( row=0; row<nRows; row++ ) {
            bitStrs[row] = bitStrs[0] + row*(nelem+1);
            idx = (row)*( (nelem+7)/8 ) + 1;
            for(len=0; len<nelem; len++) {
               if( ((char*)icol->array)[idx] & (1<<(7-len%8)) )
                  bitStrs[row][len] = '1';
               else
                  bitStrs[row][len] = '0';
               if( len%8==7 ) idx++;
            }
            bitStrs[row][len] = '\0';
         }
         varData->undef = (char*)bitStrs;
         varData->data  = (char*)bitStrs;
         break;

      case STRING:
         sptr = (char**)icol->array;
         if (varData->undef)
            free( varData->undef );
         varData->undef = (char*)malloc( nRows*sizeof(char) );
         if( varData->undef==NULL ) {
            gParse.status = MEMORY_ALLOCATION;
            break;
         }
         row = nRows;
         while( row-- )
            varData->undef[row] =
               ( **sptr != '\0' && FSTRCMP( sptr[0], sptr[row+1] )==0 );
         varData->data  = sptr + 1;
         break;

      case BOOLEAN:
         barray = (char*)icol->array;
         if (varData->undef)
            free( varData->undef );
         varData->undef = (char*)malloc( len*sizeof(char) );
         if( varData->undef==NULL ) {
            gParse.status = MEMORY_ALLOCATION;
            break;
         }
         while( len-- ) {
            varData->undef[len] = 
               ( barray[0]!=0 && barray[0]==barray[len+1] );
         }
         varData->data  = barray + 1;
         break;

      case LONG:
         iarray = (long*)icol->array;
         if (varData->undef)
            free( varData->undef );
         varData->undef = (char*)malloc( len*sizeof(char) );
         if( varData->undef==NULL ) {
            gParse.status = MEMORY_ALLOCATION;
            break;
         }
         while( len-- ) {
            varData->undef[len] = 
               ( iarray[0]!=0L && iarray[0]==iarray[len+1] );
         }
         varData->data  = iarray + 1;
         break;

      case DOUBLE:
         rarray = (double*)icol->array;
         if (varData->undef)
            free( varData->undef );
         varData->undef = (char*)malloc( len*sizeof(char) );
         if( varData->undef==NULL ) {
            gParse.status = MEMORY_ALLOCATION;
            break;
         }
         while( len-- ) {
            varData->undef[len] = 
               ( rarray[0]!=0.0 && rarray[0]==rarray[len+1]);
         }
         varData->data  = rarray + 1;
         break;

      default:
         snprintf(msg, 80, "SetupDataArrays, unhandled type %d\n",
                varData->type);
         ffpmsg(msg);
      }

      if( gParse.status ) {  /*  Deallocate NULL arrays of previous columns */
         while( i-- ) {
            varData = gParse.varData + i;
            if( varData->type==BITSTR )
               FREE( ((char**)varData->data)[0] );
            FREE( varData->undef );
            varData->undef = NULL;
         }
         return;
      }
   }
}

/*--------------------------------------------------------------------------*/
int ffcvtn( int   inputType,  /* I - Data type of input array               */
            void  *input,     /* I - Input array of type inputType          */
            char  *undef,     /* I - Array of flags indicating UNDEF elems  */
            long  ntodo,      /* I - Number of elements to process          */
            int   outputType, /* I - Data type of output array              */
            void  *nulval,    /* I - Ptr to value to use for UNDEF elements */
            void  *output,    /* O - Output array of type outputType        */
            int   *anynull,   /* O - Any nulls flagged?                     */
            int   *status )   /* O - Error status                           */
/*                                                                          */
/* Convert an array of any input data type to an array of any output        */
/* data type, using an array of UNDEF flags to assign nulvals to            */
/*--------------------------------------------------------------------------*/
{
   long i;

   switch( outputType ) {

   case TLOGICAL:
      switch( inputType ) {
      case TLOGICAL:
      case TBYTE:
         for( i=0; i<ntodo; i++ )
            if( ((unsigned char*)input)[i] )
                ((unsigned char*)output)[i] = 1;
            else
                ((unsigned char*)output)[i] = 0;
         break;
      case TSHORT:
         for( i=0; i<ntodo; i++ )
            if( ((short*)input)[i] )
                ((unsigned char*)output)[i] = 1;
            else
                ((unsigned char*)output)[i] = 0;
         break;
      case TLONG:
         for( i=0; i<ntodo; i++ )
            if( ((long*)input)[i] )
                ((unsigned char*)output)[i] = 1;
            else
                ((unsigned char*)output)[i] = 0;
         break;
      case TFLOAT:
         for( i=0; i<ntodo; i++ )
            if( ((float*)input)[i] )
                ((unsigned char*)output)[i] = 1;
            else
                ((unsigned char*)output)[i] = 0;
         break;
      case TDOUBLE:
         for( i=0; i<ntodo; i++ )
            if( ((double*)input)[i] )
                ((unsigned char*)output)[i] = 1;
            else
                ((unsigned char*)output)[i] = 0;
         break;
      default:
         *status = BAD_DATATYPE;
         break;
      }
      for(i=0;i<ntodo;i++) {
         if( undef[i] ) {
            ((unsigned char*)output)[i] = *(unsigned char*)nulval;
            *anynull = 1;
         }
      }
      break;

   case TBYTE:
      switch( inputType ) {
      case TLOGICAL:
      case TBYTE:
         for( i=0; i<ntodo; i++ )
            ((unsigned char*)output)[i] = ((unsigned char*)input)[i];
         break;
      case TSHORT:
         fffi2i1((short*)input,ntodo,1.,0.,0,0,0,NULL,NULL,(unsigned char*)output,status);
         break;
      case TLONG:
         for (i = 0; i < ntodo; i++) {
            if( undef[i] ) {
               ((unsigned char*)output)[i] = *(unsigned char*)nulval;
               *anynull = 1;
            } else {
               if( ((long*)input)[i] < 0 ) {
                  *status = OVERFLOW_ERR;
                  ((unsigned char*)output)[i] = 0;
               } else if( ((long*)input)[i] > UCHAR_MAX ) {
                  *status = OVERFLOW_ERR;
                  ((unsigned char*)output)[i] = UCHAR_MAX;
               } else
                  ((unsigned char*)output)[i] = 
                     (unsigned char) ((long*)input)[i];
            }
         }
         return( *status );
      case TFLOAT:
         fffr4i1((float*)input,ntodo,1.,0.,0,0,NULL,NULL,
                 (unsigned char*)output,status);
         break;
      case TDOUBLE:
         fffr8i1((double*)input,ntodo,1.,0.,0,0,NULL,NULL,
                 (unsigned char*)output,status);
         break;
      default:
         *status = BAD_DATATYPE;
         break;
      }
      for(i=0;i<ntodo;i++) {
         if( undef[i] ) {
            ((unsigned char*)output)[i] = *(unsigned char*)nulval;
            *anynull = 1;
         }
      }
      break;

   case TSHORT:
      switch( inputType ) {
      case TLOGICAL:
      case TBYTE:
         for( i=0; i<ntodo; i++ )
            ((short*)output)[i] = ((unsigned char*)input)[i];
         break;
      case TSHORT:
         for( i=0; i<ntodo; i++ )
            ((short*)output)[i] = ((short*)input)[i];
         break;
      case TLONG:
         for (i = 0; i < ntodo; i++) {
            if( undef[i] ) {
               ((short*)output)[i] = *(short*)nulval;
               *anynull = 1;
            } else {
               if( ((long*)input)[i] < SHRT_MIN ) {
                  *status = OVERFLOW_ERR;
                  ((short*)output)[i] = SHRT_MIN;
               } else if ( ((long*)input)[i] > SHRT_MAX ) {
                  *status = OVERFLOW_ERR;
                  ((short*)output)[i] = SHRT_MAX;
               } else
                  ((short*)output)[i] = (short) ((long*)input)[i];
            }
         }
         return( *status );
      case TFLOAT:
         fffr4i2((float*)input,ntodo,1.,0.,0,0,NULL,NULL,
                 (short*)output,status);
         break;
      case TDOUBLE:
         fffr8i2((double*)input,ntodo,1.,0.,0,0,NULL,NULL,
                 (short*)output,status);
         break;
      default:
         *status = BAD_DATATYPE;
         break;
      }
      for(i=0;i<ntodo;i++) {
         if( undef[i] ) {
            ((short*)output)[i] = *(short*)nulval;
            *anynull = 1;
         }
      }
      break;

   case TINT:
      switch( inputType ) {
      case TLOGICAL:
      case TBYTE:
         for( i=0; i<ntodo; i++ )
            ((int*)output)[i] = ((unsigned char*)input)[i];
         break;
      case TSHORT:
         for( i=0; i<ntodo; i++ )
            ((int*)output)[i] = ((short*)input)[i];
         break;
      case TLONG:
         for( i=0; i<ntodo; i++ )
            ((int*)output)[i] = ((long*)input)[i];
         break;
      case TFLOAT:
         fffr4int((float*)input,ntodo,1.,0.,0,0,NULL,NULL,
                  (int*)output,status);
         break;
      case TDOUBLE:
         fffr8int((double*)input,ntodo,1.,0.,0,0,NULL,NULL,
                  (int*)output,status);
         break;
      default:
         *status = BAD_DATATYPE;
         break;
      }
      for(i=0;i<ntodo;i++) {
         if( undef[i] ) {
            ((int*)output)[i] = *(int*)nulval;
            *anynull = 1;
         }
      }
      break;

   case TLONG:
      switch( inputType ) {
      case TLOGICAL:
      case TBYTE:
         for( i=0; i<ntodo; i++ )
            ((long*)output)[i] = ((unsigned char*)input)[i];
         break;
      case TSHORT:
         for( i=0; i<ntodo; i++ )
            ((long*)output)[i] = ((short*)input)[i];
         break;
      case TLONG:
         for( i=0; i<ntodo; i++ )
            ((long*)output)[i] = ((long*)input)[i];
         break;
      case TFLOAT:
         fffr4i4((float*)input,ntodo,1.,0.,0,0,NULL,NULL,
                 (long*)output,status);
         break;
      case TDOUBLE:
         fffr8i4((double*)input,ntodo,1.,0.,0,0,NULL,NULL,
                 (long*)output,status);
         break;
      default:
         *status = BAD_DATATYPE;
         break;
      }
      for(i=0;i<ntodo;i++) {
         if( undef[i] ) {
            ((long*)output)[i] = *(long*)nulval;
            *anynull = 1;
         }
      }
      break;

   case TLONGLONG:
      switch( inputType ) {
      case TLOGICAL:
      case TBYTE:
         for( i=0; i<ntodo; i++ )
            ((LONGLONG*)output)[i] = ((unsigned char*)input)[i];
         break;
      case TSHORT:
         for( i=0; i<ntodo; i++ )
            ((LONGLONG*)output)[i] = ((short*)input)[i];
         break;
      case TLONG:
         for( i=0; i<ntodo; i++ )
            ((LONGLONG*)output)[i] = ((long*)input)[i];
         break;
      case TFLOAT:
         fffr4i8((float*)input,ntodo,1.,0.,0,0,NULL,NULL,
                 (LONGLONG*)output,status);
         break;
      case TDOUBLE:
         fffr8i8((double*)input,ntodo,1.,0.,0,0,NULL,NULL,
                 (LONGLONG*)output,status);

         break;
      default:
         *status = BAD_DATATYPE;
         break;
      }
      for(i=0;i<ntodo;i++) {
         if( undef[i] ) {
            ((LONGLONG*)output)[i] = *(LONGLONG*)nulval;
            *anynull = 1;
         }
      }
      break;

   case TFLOAT:
      switch( inputType ) {
      case TLOGICAL:
      case TBYTE:
         for( i=0; i<ntodo; i++ )
            ((float*)output)[i] = ((unsigned char*)input)[i];
         break;
      case TSHORT:
         for( i=0; i<ntodo; i++ )
            ((float*)output)[i] = ((short*)input)[i];
         break;
      case TLONG:
         for( i=0; i<ntodo; i++ )
            ((float*)output)[i] = (float) ((long*)input)[i];
         break;
      case TFLOAT:
         for( i=0; i<ntodo; i++ )
            ((float*)output)[i] = ((float*)input)[i];
         break;
      case TDOUBLE:
         fffr8r4((double*)input,ntodo,1.,0.,0,0,NULL,NULL,
                 (float*)output,status);
         break;
      default:
         *status = BAD_DATATYPE;
         break;
      }
      for(i=0;i<ntodo;i++) {
         if( undef[i] ) {
            ((float*)output)[i] = *(float*)nulval;
            *anynull = 1;
         }
      }
      break;

   case TDOUBLE:
      switch( inputType ) {
      case TLOGICAL:
      case TBYTE:
         for( i=0; i<ntodo; i++ )
            ((double*)output)[i] = ((unsigned char*)input)[i];
         break;
      case TSHORT:
         for( i=0; i<ntodo; i++ )
            ((double*)output)[i] = ((short*)input)[i];
         break;
      case TLONG:
         for( i=0; i<ntodo; i++ )
            ((double*)output)[i] = ((long*)input)[i];
         break;
      case TFLOAT:
         for( i=0; i<ntodo; i++ )
            ((double*)output)[i] = ((float*)input)[i];
         break;
      case TDOUBLE:
         for( i=0; i<ntodo; i++ )
            ((double*)output)[i] = ((double*)input)[i];
         break;
      default:
         *status = BAD_DATATYPE;
         break;
      }
      for(i=0;i<ntodo;i++) {
         if( undef[i] ) {
            ((double*)output)[i] = *(double*)nulval;
            *anynull = 1;
         }
      }
      break;

   default:
      *status = BAD_DATATYPE;
      break;
   }

   return ( *status );
}

/*---------------------------------------------------------------------------*/
int fffrwc( fitsfile *fptr,        /* I - Input FITS file                    */
            char     *expr,        /* I - Boolean expression                 */
            char     *timeCol,     /* I - Name of time column                */
            char     *parCol,      /* I - Name of parameter column           */
            char     *valCol,      /* I - Name of value column               */
            long     ntimes,       /* I - Number of distinct times in file   */
            double   *times,       /* O - Array of times in file             */
            char     *time_status, /* O - Array of boolean results           */
            int      *status )     /* O - Error status                       */
/*                                                                           */
/* Evaluate a boolean expression for each time in a compressed file,         */
/* returning an array of flags indicating which times evaluated to TRUE/FALSE*/
/*---------------------------------------------------------------------------*/
{
   parseInfo Info;
   long alen, width;
   int parNo, typecode;
   int naxis, constant, nCol=0;
   long nelem, naxes[MAXDIMS], elem;
   char result;

   if( *status ) return( *status );

   fits_get_colnum( fptr, CASEINSEN, timeCol, &gParse.timeCol, status );
   fits_get_colnum( fptr, CASEINSEN, parCol,  &gParse.parCol , status );
   fits_get_colnum( fptr, CASEINSEN, valCol,  &gParse.valCol, status );
   if( *status ) return( *status );
   
   if( ffiprs( fptr, 1, expr, MAXDIMS, &Info.datatype, &nelem,
               &naxis, naxes, status ) ) {
      ffcprs();
      return( *status );
   }
   if( nelem<0 ) {
      constant = 1;
      nelem = -nelem;
      nCol = gParse.nCols;
      gParse.nCols = 0;    /*  Ignore all column references  */
   } else
      constant = 0;

   if( Info.datatype!=TLOGICAL || nelem!=1 ) {
      ffcprs();
      ffpmsg("Expression does not evaluate to a logical scalar.");
      return( *status = PARSE_BAD_TYPE );
   }

   /*******************************************/
   /* Allocate data arrays for each parameter */
   /*******************************************/
   
   parNo = gParse.nCols;
   while( parNo-- ) {
      switch( gParse.colData[parNo].datatype ) {
      case TLONG:
         if( (gParse.colData[parNo].array =
              (long *)malloc( (ntimes+1)*sizeof(long) )) )
            ((long*)gParse.colData[parNo].array)[0] = 1234554321;
         else
            *status = MEMORY_ALLOCATION;
         break;
      case TDOUBLE:
         if( (gParse.colData[parNo].array =
              (double *)malloc( (ntimes+1)*sizeof(double) )) )
            ((double*)gParse.colData[parNo].array)[0] = DOUBLENULLVALUE;
         else
            *status = MEMORY_ALLOCATION;
         break;
      case TSTRING:
         if( !fits_get_coltype( fptr, gParse.valCol, &typecode,
                                &alen, &width, status ) ) {
            alen++;
            if( (gParse.colData[parNo].array =
                 (char **)malloc( (ntimes+1)*sizeof(char*) )) ) {
               if( (((char **)gParse.colData[parNo].array)[0] =
                    (char *)malloc( (ntimes+1)*sizeof(char)*alen )) ) {
                  for( elem=1; elem<=ntimes; elem++ )
                     ((char **)gParse.colData[parNo].array)[elem] =
                        ((char **)gParse.colData[parNo].array)[elem-1]+alen;
                  ((char **)gParse.colData[parNo].array)[0][0] = '\0';
               } else {
                  free( gParse.colData[parNo].array );
                  *status = MEMORY_ALLOCATION;
               }
            } else {
               *status = MEMORY_ALLOCATION;
            }
         }
         break;
      }
      if( *status ) {
         while( parNo-- ) {
            if( gParse.colData[parNo].datatype==TSTRING )
               FREE( ((char **)gParse.colData[parNo].array)[0] );
            FREE( gParse.colData[parNo].array );
         }
         return( *status );
      }
   }
   
   /**********************************************************************/
   /* Read data from columns needed for the expression and then parse it */
   /**********************************************************************/
   
   if( !uncompress_hkdata( fptr, ntimes, times, status ) ) {
      if( constant ) {
         result = gParse.Nodes[gParse.resultNode].value.data.log;
         elem = ntimes;
         while( elem-- ) time_status[elem] = result;
      } else {
         Info.dataPtr  = time_status;
         Info.nullPtr  = NULL;
         Info.maxRows  = ntimes;
         *status       = parse_data( ntimes, 0, 1, ntimes, gParse.nCols,
                                     gParse.colData, (void*)&Info );
      }
   }
   
   /************/
   /* Clean up */
   /************/
   
   parNo = gParse.nCols;
   while ( parNo-- ) {
      if( gParse.colData[parNo].datatype==TSTRING )
         FREE( ((char **)gParse.colData[parNo].array)[0] );
      FREE( gParse.colData[parNo].array );
   }
   
   if( constant ) gParse.nCols = nCol;

   ffcprs();
   return(*status);
}

/*---------------------------------------------------------------------------*/
int uncompress_hkdata( fitsfile *fptr,
                       long     ntimes,
                       double   *times,
                       int      *status )
/*                                                                           */
/* description                                                               */
/*---------------------------------------------------------------------------*/
{
   char parName[256], *sPtr[1], found[1000];
   int parNo, anynul;
   long naxis2, row, currelem;
   double currtime, newtime;

   sPtr[0] = parName;
   currelem = 0;
   currtime = -1e38;

   parNo=gParse.nCols;
   while( parNo-- ) found[parNo] = 0;

   if( ffgkyj( fptr, "NAXIS2", &naxis2, NULL, status ) ) return( *status );

   for( row=1; row<=naxis2; row++ ) {
      if( ffgcvd( fptr, gParse.timeCol, row, 1L, 1L, 0.0,
                  &newtime, &anynul, status ) ) return( *status );
      if( newtime != currtime ) {
         /*  New time encountered... propogate parameters to next row  */
         if( currelem==ntimes ) {
            ffpmsg("Found more unique time stamps than caller indicated");
            return( *status = PARSE_BAD_COL );
         }
         times[currelem++] = currtime = newtime;
         parNo = gParse.nCols;
         while( parNo-- ) {
            switch( gParse.colData[parNo].datatype ) {
            case TLONG:
               ((long*)gParse.colData[parNo].array)[currelem] =
                  ((long*)gParse.colData[parNo].array)[currelem-1];
               break;
            case TDOUBLE:
               ((double*)gParse.colData[parNo].array)[currelem] =
                  ((double*)gParse.colData[parNo].array)[currelem-1];
               break;
            case TSTRING:
               strcpy( ((char **)gParse.colData[parNo].array)[currelem],
                       ((char **)gParse.colData[parNo].array)[currelem-1] );
               break;
            }
         }
      }

      if( ffgcvs( fptr, gParse.parCol, row, 1L, 1L, "",
                  sPtr, &anynul, status ) ) return( *status );
      parNo = gParse.nCols;
      while( parNo-- )
         if( !fits_strcasecmp( parName, gParse.varData[parNo].name ) ) break;

      if( parNo>=0 ) {
         found[parNo] = 1; /* Flag this parameter as found */
         switch( gParse.colData[parNo].datatype ) {
         case TLONG:
            ffgcvj( fptr, gParse.valCol, row, 1L, 1L,
                    ((long*)gParse.colData[parNo].array)[0],
                    ((long*)gParse.colData[parNo].array)+currelem,
                    &anynul, status );
            break;
         case TDOUBLE:
            ffgcvd( fptr, gParse.valCol, row, 1L, 1L,
                    ((double*)gParse.colData[parNo].array)[0],
                    ((double*)gParse.colData[parNo].array)+currelem,
                    &anynul, status );
            break;
         case TSTRING:
            ffgcvs( fptr, gParse.valCol, row, 1L, 1L,
                    ((char**)gParse.colData[parNo].array)[0],
                    ((char**)gParse.colData[parNo].array)+currelem,
                    &anynul, status );
            break;
         }
         if( *status ) return( *status );
      }
   }

   if( currelem<ntimes ) {
      ffpmsg("Found fewer unique time stamps than caller indicated");
      return( *status = PARSE_BAD_COL );
   }

   /*  Check for any parameters which were not located in the table  */
   parNo = gParse.nCols;
   while( parNo-- )
      if( !found[parNo] ) {
         snprintf( parName, 256, "Parameter not found: %-30s", 
                  gParse.varData[parNo].name );
         ffpmsg( parName );
         *status = PARSE_SYNTAX_ERR;
      }
   return( *status );
}

/*---------------------------------------------------------------------------*/
int ffffrw( fitsfile *fptr,         /* I - Input FITS file                   */
            char     *expr,         /* I - Boolean expression                */
            long     *rownum,       /* O - First row of table to eval to T   */
            int      *status )      /* O - Error status                      */
/*                                                                           */
/* Evaluate a boolean expression, returning the row number of the first      */
/* row which evaluates to TRUE                                               */
/*---------------------------------------------------------------------------*/
{
   int naxis, constant, dtype;
   long nelem, naxes[MAXDIMS];
   char result;

   if( *status ) return( *status );

   FFLOCK;
   if( ffiprs( fptr, 0, expr, MAXDIMS, &dtype, &nelem, &naxis,
               naxes, status ) ) {
      ffcprs();
      FFUNLOCK;
      return( *status );
   }
   if( nelem<0 ) {
      constant = 1;
      nelem = -nelem;
   } else
      constant = 0;

   if( dtype!=TLOGICAL || nelem!=1 ) {
      ffcprs();
      ffpmsg("Expression does not evaluate to a logical scalar.");
      FFUNLOCK;
      return( *status = PARSE_BAD_TYPE );
   }

   *rownum = 0;
   if( constant ) { /* No need to call parser... have result from ffiprs */
      result = gParse.Nodes[gParse.resultNode].value.data.log;
      if( result ) {
         /*  Make sure there is at least 1 row in table  */
         ffgnrw( fptr, &nelem, status );
         if( nelem )
            *rownum = 1;
      }
   } else {
      if( ffiter( gParse.nCols, gParse.colData, 0, 0,
                  ffffrw_work, (void*)rownum, status ) == -1 )
         *status = 0;  /* -1 indicates exitted without error before end... OK */
   }

   ffcprs();
   FFUNLOCK;
   return(*status);
}

/*---------------------------------------------------------------------------*/
int ffffrw_work(long        totalrows, /* I - Total rows to be processed     */
                long        offset,    /* I - Number of rows skipped at start*/
                long        firstrow,  /* I - First row of this iteration    */
                long        nrows,     /* I - Number of rows in this iter    */
                int         nCols,     /* I - Number of columns in use       */
                iteratorCol *colData,  /* IO- Column information/data        */
                void        *userPtr ) /* I - Data handling instructions     */
/*                                                                           */
/* Iterator work function which calls the parser and searches for the        */
/* first row which evaluates to TRUE.                                        */
/*---------------------------------------------------------------------------*/
{
    long idx;
    Node *result;

    Evaluate_Parser( firstrow, nrows );

    if( !gParse.status ) {

       result = gParse.Nodes + gParse.resultNode;
       if( result->operation==CONST_OP ) {

          if( result->value.data.log ) {
             *(long*)userPtr = firstrow;
             return( -1 );
          }

       } else {

          for( idx=0; idx<nrows; idx++ )
             if( result->value.data.logptr[idx] && !result->value.undef[idx] ) {
                *(long*)userPtr = firstrow + idx;
                return( -1 );
             }
       }
    }

    return( gParse.status );
}


static int set_image_col_types (fitsfile * fptr, const char * name, int bitpix,
                DataInfo * varInfo, iteratorCol *colIter) {

   int istatus;
   double tscale, tzero;
   char temp[80];

   switch (bitpix) {
      case BYTE_IMG:
      case SHORT_IMG:
      case LONG_IMG:
         istatus = 0;
         if (fits_read_key(fptr, TDOUBLE, "BZERO", &tzero, NULL, &istatus))
            tzero = 0.0;

         istatus = 0;
         if (fits_read_key(fptr, TDOUBLE, "BSCALE", &tscale, NULL, &istatus))
            tscale = 1.0;

         if (tscale == 1.0 && (tzero == 0.0 || tzero == 32768.0 )) {
            varInfo->type     = LONG;
            colIter->datatype = TLONG;
         }
         else {
            varInfo->type     = DOUBLE;
            colIter->datatype = TDOUBLE;
            if (DEBUG_PIXFILTER)
                printf("use DOUBLE for %s with BSCALE=%g/BZERO=%g\n",
                        name, tscale, tzero);
         }
         break;

      case LONGLONG_IMG:
      case FLOAT_IMG:
      case DOUBLE_IMG:
         varInfo->type     = DOUBLE;
         colIter->datatype = TDOUBLE;
         break;
      default:
         snprintf(temp, 80,"set_image_col_types: unrecognized image bitpix [%d]\n",
                bitpix);
         ffpmsg(temp);
         return gParse.status = PARSE_BAD_TYPE;
   }
   return 0;
}


/*************************************************************************

        Functions used by the evaluator to access FITS data
            (find_column, find_keywd, allocateCol, load_column)

 *************************************************************************/

static int find_column( char *colName, void *itslval )
{
   FFSTYPE *thelval = (FFSTYPE*)itslval;
   int col_cnt, status;
   int colnum, typecode, type;
   long repeat, width;
   fitsfile *fptr;
   char temp[80];
   double tzero,tscale;
   int istatus;
   DataInfo *varInfo;
   iteratorCol *colIter;

if (DEBUG_PIXFILTER)
   printf("find_column(%s)\n", colName);

   if( *colName == '#' )
      return( find_keywd( colName + 1, itslval ) );

   fptr = gParse.def_fptr;

   status = 0;
   col_cnt = gParse.nCols;

if (gParse.hdutype == IMAGE_HDU) {
   int i;
   if (!gParse.pixFilter) {
      gParse.status = COL_NOT_FOUND;
      ffpmsg("find_column: IMAGE_HDU but no PixelFilter");
      return pERROR;
   }

   colnum = -1;
   for (i = 0; i < gParse.pixFilter->count; ++i) {
      if (!fits_strcasecmp(colName, gParse.pixFilter->tag[i]))
         colnum = i;
   }
   if (colnum < 0) {
      snprintf(temp, 80, "find_column: PixelFilter tag %s not found", colName);
      ffpmsg(temp);
      gParse.status = COL_NOT_FOUND;
      return pERROR;
   }

   if( allocateCol( col_cnt, &gParse.status ) ) return pERROR;

   varInfo = gParse.varData + col_cnt;
   colIter = gParse.colData + col_cnt;

   fptr = gParse.pixFilter->ifptr[colnum];
   fits_get_img_param(fptr,
                MAXDIMS,
                &typecode, /* actually bitpix */
                &varInfo->naxis,
                &varInfo->naxes[0],
                &status);
   varInfo->nelem = 1;
   type = COLUMN;
   if (set_image_col_types(fptr, colName, typecode, varInfo, colIter))
      return pERROR;
   colIter->fptr = fptr;
   colIter->iotype = InputCol;
}
else { /* HDU holds a table */
   if( gParse.compressed )
      colnum = gParse.valCol;
   else
      if( fits_get_colnum( fptr, CASEINSEN, colName, &colnum, &status ) ) {
         if( status == COL_NOT_FOUND ) {
            type = find_keywd( colName, itslval );
            if( type != pERROR ) ffcmsg();
            return( type );
         }
         gParse.status = status;
         return pERROR;
      }
   
   if( fits_get_coltype( fptr, colnum, &typecode,
                         &repeat, &width, &status ) ) {
      gParse.status = status;
      return pERROR;
   }

   if( allocateCol( col_cnt, &gParse.status ) ) return pERROR;

   varInfo = gParse.varData + col_cnt;
   colIter = gParse.colData + col_cnt;

   fits_iter_set_by_num( colIter, fptr, colnum, 0, InputCol );
}

   /*  Make sure we don't overflow variable name array  */
   strncpy(varInfo->name,colName,MAXVARNAME);
   varInfo->name[MAXVARNAME] = '\0';

if (gParse.hdutype != IMAGE_HDU) {
   switch( typecode ) {
   case TBIT:
      varInfo->type     = BITSTR;
      colIter->datatype = TBYTE;
      type = BITCOL;
      break;
   case TBYTE:
   case TSHORT:
   case TLONG:
      /* The datatype of column with TZERO and TSCALE keywords might be 
         float or double. 
      */
      snprintf(temp,80,"TZERO%d",colnum);
      istatus = 0;
      if(fits_read_key(fptr,TDOUBLE,temp,&tzero,NULL,&istatus)) {
          tzero = 0.0;
      } 
      snprintf(temp,80,"TSCAL%d",colnum);
      istatus = 0;
      if(fits_read_key(fptr,TDOUBLE,temp,&tscale,NULL,&istatus)) {
          tscale = 1.0;
      } 
      if (tscale == 1.0 && (tzero == 0.0 || tzero == 32768.0 )) {
          varInfo->type     = LONG;
          colIter->datatype = TLONG;
/*    Reading an unsigned long column as a long can cause overflow errors.
      Treat the column as a double instead.
      } else if (tscale == 1.0 &&  tzero == 2147483648.0 ) {
          varInfo->type     = LONG;
          colIter->datatype = TULONG;
 */

      }
      else {
          varInfo->type     = DOUBLE;
          colIter->datatype = TDOUBLE;
      }
      type = COLUMN;
      break;
/* 
  For now, treat 8-byte integer columns as type double.
  This can lose precision, so the better long term solution
  will be to add support for TLONGLONG as a separate datatype.
*/
   case TLONGLONG:
   case TFLOAT:
   case TDOUBLE:
      varInfo->type     = DOUBLE;
      colIter->datatype = TDOUBLE;
      type = COLUMN;
      break;
   case TLOGICAL:
      varInfo->type     = BOOLEAN;
      colIter->datatype = TLOGICAL;
      type = BCOLUMN;
      break;
   case TSTRING:
      varInfo->type     = STRING;
      colIter->datatype = TSTRING;
      type = SCOLUMN;
      if ( width >= MAX_STRLEN ) {
	snprintf(temp, 80, "column %d is wider than maximum %d characters",
		colnum, MAX_STRLEN-1);
        ffpmsg(temp);
	gParse.status = PARSE_LRG_VECTOR;
	return pERROR;
      }
      if( gParse.hdutype == ASCII_TBL ) repeat = width;
      break;
   default:
      if (typecode < 0) {
        snprintf(temp, 80,"variable-length array columns are not supported. typecode = %d", typecode);
        ffpmsg(temp);
      }
      gParse.status = PARSE_BAD_TYPE;
      return pERROR;
   }
   varInfo->nelem = repeat;
   if( repeat>1 && typecode!=TSTRING ) {
      if( fits_read_tdim( fptr, colnum, MAXDIMS,
                          &varInfo->naxis,
                          &varInfo->naxes[0], &status )
          ) {
         gParse.status = status;
         return pERROR;
      }
   } else {
      varInfo->naxis = 1;
      varInfo->naxes[0] = 1;
   }
}
   gParse.nCols++;
   thelval->lng = col_cnt;

   return( type );
}

static int find_keywd(char *keyname, void *itslval )
{
   FFSTYPE *thelval = (FFSTYPE*)itslval;
   int status, type;
   char keyvalue[FLEN_VALUE], dtype;
   fitsfile *fptr;
   double rval;
   int bval;
   long ival;

   status = 0;
   fptr = gParse.def_fptr;
   if( fits_read_keyword( fptr, keyname, keyvalue, NULL, &status ) ) {
      if( status == KEY_NO_EXIST ) {
         /*  Do this since ffgkey doesn't put an error message on stack  */
         snprintf(keyvalue,FLEN_VALUE, "ffgkey could not find keyword: %s",keyname);
         ffpmsg(keyvalue);
      }
      gParse.status = status;
      return( pERROR );
   }
      
   if( fits_get_keytype( keyvalue, &dtype, &status ) ) {
      gParse.status = status;
      return( pERROR );
   }
      
   switch( dtype ) {
   case 'C':
      fits_read_key_str( fptr, keyname, keyvalue, NULL, &status );
      type = STRING;
      strcpy( thelval->str , keyvalue );
      break;
   case 'L':
      fits_read_key_log( fptr, keyname, &bval, NULL, &status );
      type = BOOLEAN;
      thelval->log = bval;
      break;
   case 'I':
      fits_read_key_lng( fptr, keyname, &ival, NULL, &status );
      type = LONG;
      thelval->lng = ival;
      break;
   case 'F':
      fits_read_key_dbl( fptr, keyname, &rval, NULL, &status );
      type = DOUBLE;
      thelval->dbl = rval;
      break;
   default:
      type = pERROR;
      break;
   }

   if( status ) {
      gParse.status=status;
      return pERROR;
   }

   return( type );
}

static int allocateCol( int nCol, int *status )
{
   if( (nCol%25)==0 ) {
      if( nCol ) {
         gParse.colData  = (iteratorCol*) realloc( gParse.colData,
                                              (nCol+25)*sizeof(iteratorCol) );
         gParse.varData  = (DataInfo   *) realloc( gParse.varData,
                                              (nCol+25)*sizeof(DataInfo)    );
      } else {
         gParse.colData  = (iteratorCol*) malloc( 25*sizeof(iteratorCol) );
         gParse.varData  = (DataInfo   *) malloc( 25*sizeof(DataInfo)    );
      }
      if(    gParse.colData  == NULL
          || gParse.varData  == NULL    ) {
         if( gParse.colData  ) free(gParse.colData);
         if( gParse.varData  ) free(gParse.varData);
         gParse.colData = NULL;
         gParse.varData = NULL;
         return( *status = MEMORY_ALLOCATION );
      }
   }
   gParse.varData[nCol].data  = NULL;
   gParse.varData[nCol].undef = NULL;
   return 0;
}

static int load_column( int varNum, long fRow, long nRows,
                        void *data, char *undef )
{
   iteratorCol *var = gParse.colData+varNum;
   long nelem,nbytes,row,len,idx;
   char **bitStrs, msg[80];
   unsigned char *bytes;
   int status = 0, anynul;

  if (gParse.hdutype == IMAGE_HDU) {
    /* This test would need to be on a per varNum basis to support
     * cross HDU operations */
    fits_read_imgnull(var->fptr, var->datatype, fRow, nRows,
                data, undef, &anynul, &status);
    if (DEBUG_PIXFILTER)
        printf("load_column: IMAGE_HDU fRow=%ld, nRows=%ld => %d\n",
                        fRow, nRows, status);
  } else { 

   nelem = nRows * var->repeat;

   switch( var->datatype ) {
   case TBYTE:
      nbytes = ((var->repeat+7)/8) * nRows;
      bytes = (unsigned char *)malloc( nbytes * sizeof(char) );

      ffgcvb(var->fptr, var->colnum, fRow, 1L, nbytes,
             0, bytes, &anynul, &status);

      nelem = var->repeat;
      bitStrs = (char **)data;
      for( row=0; row<nRows; row++ ) {
         idx = (row)*( (nelem+7)/8 ) + 1;
         for(len=0; len<nelem; len++) {
            if( bytes[idx] & (1<<(7-len%8)) )
               bitStrs[row][len] = '1';
            else
               bitStrs[row][len] = '0';
            if( len%8==7 ) idx++;
         }
         bitStrs[row][len] = '\0';
      }

      FREE( (char *)bytes );
      break;
   case TSTRING:
      ffgcfs(var->fptr, var->colnum, fRow, 1L, nRows,
             (char **)data, undef, &anynul, &status);
      break;
   case TLOGICAL:
      ffgcfl(var->fptr, var->colnum, fRow, 1L, nelem,
             (char *)data, undef, &anynul, &status);
      break;
   case TLONG:
      ffgcfj(var->fptr, var->colnum, fRow, 1L, nelem,
             (long *)data, undef, &anynul, &status);
      break;
   case TDOUBLE:
      ffgcfd(var->fptr, var->colnum, fRow, 1L, nelem,
             (double *)data, undef, &anynul, &status);
      break;
   default:
      snprintf(msg,80,"load_column: unexpected datatype %d", var->datatype);
      ffpmsg(msg);
   }
  }
   if( status ) {
      gParse.status = status;
      return pERROR;
   }

   return 0;
}


/*--------------------------------------------------------------------------*/
int fits_pixel_filter (PixelFilter * filter, int * status)
/* Evaluate an expression using the data in the input FITS file(s)          */
/*--------------------------------------------------------------------------*/
{
   parseInfo Info = { 0 };
   int naxis, bitpix;
   long nelem, naxes[MAXDIMS];
   int col_cnt;
   Node *result;
   int datatype;
   fitsfile * infptr;
   fitsfile * outfptr;
   char * DEFAULT_TAGS[] = { "X" };
   char msg[256];
   int writeBlankKwd = 0;   /* write BLANK if any output nulls? */

   DEBUG_PIXFILTER = getenv("DEBUG_PIXFILTER") ? 1 : 0;

   if (*status)
      return (*status);

   FFLOCK;
   if (!filter->tag || !filter->tag[0] || !filter->tag[0][0]) {
      filter->tag = DEFAULT_TAGS;
      if (DEBUG_PIXFILTER)
         printf("using default tag '%s'\n", filter->tag[0]);
   }

   infptr = filter->ifptr[0];
   outfptr = filter->ofptr;
   gParse.pixFilter = filter;

   if (ffiprs(infptr, 0, filter->expression, MAXDIMS,
            &Info.datatype, &nelem, &naxis, naxes, status)) {
      goto CLEANUP;
   }

   if (nelem < 0) {
      nelem = -nelem;
   }

   {
      /* validate result type */
      const char * type = 0;
      switch (Info.datatype) {
         case TLOGICAL:  type = "LOGICAL"; break;
         case TLONG:     type = "LONG"; break;
         case TDOUBLE:   type = "DOUBLE"; break;
         case TSTRING:   type = "STRING";
                         *status = pERROR;
                         ffpmsg("pixel_filter: cannot have string image");
         case TBIT:      type = "BIT";
                         if (DEBUG_PIXFILTER)
                            printf("hmm, image from bits?\n");
                         break;
         default:       type = "UNKNOWN?!";
                        *status = pERROR;
                        ffpmsg("pixel_filter: unexpected result datatype");
      }
      if (DEBUG_PIXFILTER)
         printf("result type is %s [%d]\n", type, Info.datatype);
      if (*status)
         goto CLEANUP;
   }

   if (fits_get_img_param(infptr, MAXDIMS,
            &bitpix, &naxis, &naxes[0], status)) {
      ffpmsg("pixel_filter: unable to read input image parameters");
      goto CLEANUP;
   }

   if (DEBUG_PIXFILTER)
      printf("input bitpix %d\n", bitpix);

   if (Info.datatype == TDOUBLE) {
       /*  for floating point expressions, set the default output image to
           bitpix = -32 (float) unless the default is already a double */
       if (bitpix != DOUBLE_IMG)
           bitpix = FLOAT_IMG;
   }

   /* override output image bitpix if specified by caller */
   if (filter->bitpix)
      bitpix = filter->bitpix;
   if (DEBUG_PIXFILTER)
      printf("output bitpix %d\n", bitpix);

   if (fits_create_img(outfptr, bitpix, naxis, naxes, status)) {
      ffpmsg("pixel_filter: unable to create output image");
      goto CLEANUP;
   }

   /* transfer keycards */
   {
      int i, ncards, more;
      if (fits_get_hdrspace(infptr, &ncards, &more, status)) {
         ffpmsg("pixel_filter: unable to determine number of keycards");
         goto CLEANUP;
      }

      for (i = 1; i <= ncards; ++i) {

         int keyclass;
         char card[FLEN_CARD];

         if (fits_read_record(infptr, i, card, status)) {
            snprintf(msg, 256,"pixel_filter: unable to read keycard %d", i);
            ffpmsg(msg);
            goto CLEANUP;
         }

         keyclass = fits_get_keyclass(card);
         if (keyclass == TYP_STRUC_KEY) {
            /* output structure defined by fits_create_img */
         }
         else if (keyclass == TYP_COMM_KEY && i < 12) {
            /* assume this is one of the FITS standard comments */
         }
         else if (keyclass == TYP_NULL_KEY && bitpix < 0) {
            /* do not transfer BLANK to real output image */
         }
         else if (keyclass == TYP_SCAL_KEY && bitpix < 0) {
            /* do not transfer BZERO, BSCALE to real output image */
         }
         else if (fits_write_record(outfptr, card, status)) {
            snprintf(msg,256, "pixel_filter: unable to write keycard '%s' [%d]\n",
                        card, *status);
            ffpmsg(msg);
            goto CLEANUP;
         }
      }
   }

   switch (bitpix) {
      case BYTE_IMG: datatype = TLONG; Info.datatype = TBYTE; break;
      case SHORT_IMG: datatype = TLONG; Info.datatype = TSHORT; break;
      case LONG_IMG: datatype = TLONG; Info.datatype = TLONG; break;
      case FLOAT_IMG: datatype = TDOUBLE; Info.datatype = TFLOAT; break;
      case DOUBLE_IMG: datatype = TDOUBLE; Info.datatype = TDOUBLE; break;

      default:
           snprintf(msg, 256,"pixel_filter: unexpected output bitpix %d\n", bitpix);
           ffpmsg(msg);
           *status = pERROR;
           goto CLEANUP;
   }

   if (bitpix > 0) { /* arrange for NULLs in output */
      long nullVal = filter->blank;
      if (!filter->blank) {
         int tstatus = 0;
         if (fits_read_key_lng(infptr, "BLANK", &nullVal, 0, &tstatus)) {

            writeBlankKwd = 1;

            if (bitpix == BYTE_IMG)
                nullVal = UCHAR_MAX;
            else if (bitpix == SHORT_IMG)
                nullVal = SHRT_MIN;
            else if (bitpix == LONG_IMG)
                nullVal = LONG_MIN;
            else
                printf("unhandled positive output BITPIX %d\n", bitpix);
         }

         filter->blank = nullVal;
      }

      fits_set_imgnull(outfptr, filter->blank, status);
      if (DEBUG_PIXFILTER)
         printf("using blank %ld\n", nullVal);

   }

   if (!filter->keyword[0]) {
      iteratorCol * colIter;
      DataInfo * varInfo;

      /*************************************/
      /* Create new iterator Output Column */
      /*************************************/
      col_cnt = gParse.nCols;
      if (allocateCol(col_cnt, status))
         goto CLEANUP;
      gParse.nCols++;

      colIter = &gParse.colData[col_cnt];
      colIter->fptr = filter->ofptr;
      colIter->iotype = OutputCol;
      varInfo = &gParse.varData[col_cnt];
      set_image_col_types(colIter->fptr, "CREATED", bitpix, varInfo, colIter);

      Info.maxRows = -1;

      if (ffiter(gParse.nCols, gParse.colData, 0,
                     0, parse_data, &Info, status) == -1)
            *status = 0;
      else if (*status)
         goto CLEANUP;

      if (Info.anyNull) {
         if (writeBlankKwd) {
            fits_update_key_lng(outfptr, "BLANK", filter->blank, "NULL pixel value", status);
            if (*status)
                ffpmsg("pixel_filter: unable to write BLANK keyword");
            if (DEBUG_PIXFILTER) {
                printf("output has NULLs\n");
                printf("wrote blank [%d]\n", *status);
            }
         }
      }
      else if (bitpix > 0) /* never used a null */
         if (fits_set_imgnull(outfptr, -1234554321, status))
            ffpmsg("pixel_filter: unable to reset imgnull");
   }
   else {

      /* Put constant result into keyword */
      char * parName = filter->keyword;
      char * parInfo = filter->comment;

      result  = gParse.Nodes + gParse.resultNode;
      switch (Info.datatype) {
      case TDOUBLE:
         ffukyd(outfptr, parName, result->value.data.dbl, 15, parInfo, status);
         break;
      case TLONG:
         ffukyj(outfptr, parName, result->value.data.lng, parInfo, status);
         break;
      case TLOGICAL:
         ffukyl(outfptr, parName, result->value.data.log, parInfo, status);
         break;
      case TBIT:
      case TSTRING:
         ffukys(outfptr, parName, result->value.data.str, parInfo, status);
         break;
      default:
         snprintf(msg, 256,"pixel_filter: unexpected constant result type [%d]\n",
                Info.datatype);
         ffpmsg(msg);
      }
   }

CLEANUP:
   ffcprs();
   FFUNLOCK;
   return (*status);
}