| /*============================================================================ | |
| WCSLIB 6.2 - an implementation of the FITS WCS standard. | |
| Copyright (C) 1995-2018, Mark Calabretta | |
| This file is part of WCSLIB. | |
| WCSLIB is free software: you can redistribute it and/or modify it under the | |
| terms of the GNU Lesser General Public License as published by the Free | |
| Software Foundation, either version 3 of the License, or (at your option) | |
| any later version. | |
| WCSLIB is distributed in the hope that it will be useful, but WITHOUT ANY | |
| WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS | |
| FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for | |
| more details. | |
| You should have received a copy of the GNU Lesser General Public License | |
| along with WCSLIB. If not, see http://www.gnu.org/licenses. | |
| Direct correspondence concerning WCSLIB to mark@calabretta.id.au | |
| Author: Mark Calabretta, Australia Telescope National Facility, CSIRO. | |
| http://www.atnf.csiro.au/people/Mark.Calabretta | |
| $Id: wcsfix.h,v 6.2 2018/10/20 10:03:13 mcalabre Exp $ | |
| *============================================================================= | |
| * | |
| * WCSLIB 6.2 - C routines that implement the FITS World Coordinate System | |
| * (WCS) standard. Refer to the README file provided with WCSLIB for an | |
| * overview of the library. | |
| * | |
| * | |
| * Summary of the wcsfix routines | |
| * ------------------------------ | |
| * Routines in this suite identify and translate various forms of construct | |
| * known to occur in FITS headers that violate the FITS World Coordinate System | |
| * (WCS) standard described in | |
| * | |
| = "Representations of world coordinates in FITS", | |
| = Greisen, E.W., & Calabretta, M.R. 2002, A&A, 395, 1061 (WCS Paper I) | |
| = | |
| = "Representations of celestial coordinates in FITS", | |
| = Calabretta, M.R., & Greisen, E.W. 2002, A&A, 395, 1077 (WCS Paper II) | |
| = | |
| = "Representations of spectral coordinates in FITS", | |
| = Greisen, E.W., Calabretta, M.R., Valdes, F.G., & Allen, S.L. | |
| = 2006, A&A, 446, 747 (WCS Paper III) | |
| = | |
| = "Representations of time coordinates in FITS - | |
| = Time and relative dimension in space", | |
| = Rots, A.H., Bunclark, P.S., Calabretta, M.R., Allen, S.L., | |
| = Manchester, R.N., & Thompson, W.T. 2015, A&A, 574, A36 (WCS Paper VII) | |
| * | |
| * Repairs effected by these routines range from the translation of | |
| * non-standard values for standard WCS keywords, to the repair of malformed | |
| * coordinate representations. Some routines are also provided to check the | |
| * consistency of pairs of keyvalues that define the same measure in two | |
| * different ways, for example, as a date and an MJD. | |
| * | |
| * Non-standard keyvalues: | |
| * ----------------------- | |
| * AIPS-convention celestial projection types, NCP and GLS, and spectral | |
| * types, 'FREQ-LSR', 'FELO-HEL', etc., set in CTYPEia are translated | |
| * on-the-fly by wcsset() but without modifying the relevant ctype[], pv[] or | |
| * specsys members of the wcsprm struct. That is, only the information | |
| * extracted from ctype[] is translated when wcsset() fills in wcsprm::cel | |
| * (celprm struct) or wcsprm::spc (spcprm struct). | |
| * | |
| * On the other hand, these routines do change the values of wcsprm::ctype[], | |
| * wcsprm::pv[], wcsprm::specsys and other wcsprm struct members as | |
| * appropriate to produce the same result as if the FITS header itself had | |
| * been translated. | |
| * | |
| * Auxiliary WCS header information not used directly by WCSLIB may also be | |
| * translated. For example, the older DATE-OBS date format (wcsprm::dateobs) | |
| * is recast to year-2000 standard form, and MJD-OBS (wcsprm::mjdobs) will be | |
| * deduced from it if not already set. | |
| * | |
| * Certain combinations of keyvalues that result in malformed coordinate | |
| * systems, as described in Sect. 7.3.4 of Paper I, may also be repaired. | |
| * These are handled by cylfix(). | |
| * | |
| * Non-standard keywords: | |
| * ---------------------- | |
| * The AIPS-convention CROTAn keywords are recognized as quasi-standard | |
| * and as such are accomodated by wcsprm::crota[] and translated to | |
| * wcsprm::pc[][] by wcsset(). These are not dealt with here, nor are any | |
| * other non-standard keywords since these routines work only on the contents | |
| * of a wcsprm struct and do not deal with FITS headers per se. In | |
| * particular, they do not identify or translate CD00i00j, PC00i00j, PROJPn, | |
| * EPOCH, VELREF or VSOURCEa keywords; this may be done by the FITS WCS | |
| * header parser supplied with WCSLIB, refer to wcshdr.h. | |
| * | |
| * wcsfix() and wcsfixi() apply all of the corrections handled by the following | |
| * specific functions which may also be invoked separately: | |
| * | |
| * - cdfix(): Sets the diagonal element of the CDi_ja matrix to 1.0 if all | |
| * CDi_ja keywords associated with a particular axis are omitted. | |
| * | |
| * - datfix(): recast an older DATE-OBS date format in dateobs to year-2000 | |
| * standard form. | |
| * | |
| * Derive mjdobs from dateobs if not already set. Alternatively, if mjdobs | |
| * is set and dateobs isn't, then derive dateobs from it. If both are set, | |
| * then check consistency. Likewise for datebeg and mjdbeg; dateavg and | |
| * mjdavg; and dateend and mjdend. | |
| * | |
| * - obsfix(): if only one half of obsgeo[] is set, then derive the other | |
| * half from it. If both halves are set, then check consistency. | |
| * | |
| * - unitfix(): translate some commonly used but non-standard unit strings in | |
| * the CUNITia keyvalues, e.g. 'DEG' -> 'deg'. | |
| * | |
| * - spcfix(): translate AIPS-convention spectral types, 'FREQ-LSR', | |
| * 'FELO-HEL', etc., in ctype[] as set from CTYPEia. | |
| * | |
| * - celfix(): translate AIPS-convention celestial projection types, NCP and | |
| * GLS, in ctype[] as set from CTYPEia. | |
| * | |
| * - cylfix(): fixes WCS keyvalues for malformed cylindrical projections that | |
| * suffer from the problem described in Sect. 7.3.4 of Paper I. | |
| * | |
| * | |
| * wcsfix() - Translate a non-standard WCS struct | |
| * ---------------------------------------------- | |
| * wcsfix() is identical to wcsfixi(), but lacks the info argument. | |
| * | |
| * | |
| * wcsfixi() - Translate a non-standard WCS struct | |
| * ----------------------------------------------- | |
| * wcsfixi() applies all of the corrections handled separately by cdfix(), | |
| * datfix(), obsfix(), unitfix(), spcfix(), celfix(), and cylfix(). | |
| * | |
| * Given: | |
| * ctrl int Do potentially unsafe translations of non-standard | |
| * unit strings as described in the usage notes to | |
| * wcsutrn(). | |
| * | |
| * naxis const int [] | |
| * Image axis lengths. If this array pointer is set to | |
| * zero then cylfix() will not be invoked. | |
| * | |
| * Given and returned: | |
| * wcs struct wcsprm* | |
| * Coordinate transformation parameters. | |
| * | |
| * Returned: | |
| * stat int [NWCSFIX] | |
| * Status returns from each of the functions. Use the | |
| * preprocessor macros NWCSFIX to dimension this vector | |
| * and CDFIX, DATFIX, OBSFIX, UNITFIX, SPCFIX, CELFIX, | |
| * and CYLFIX to access its elements. A status value | |
| * of -2 is set for functions that were not invoked. | |
| * | |
| * info struct wcserr [NWCSFIX] | |
| * Status messages from each of the functions. Use the | |
| * preprocessor macros NWCSFIX to dimension this vector | |
| * and CDFIX, DATFIX, OBSFIX, UNITFIX, SPCFIX, CELFIX, | |
| * and CYLFIX to access its elements. | |
| * | |
| * Function return value: | |
| * int Status return value: | |
| * 0: Success. | |
| * 1: One or more of the translation functions | |
| * returned an error. | |
| * | |
| * | |
| * cdfix() - Fix erroneously omitted CDi_ja keywords | |
| * ------------------------------------------------- | |
| * cdfix() sets the diagonal element of the CDi_ja matrix to unity if all | |
| * CDi_ja keywords associated with a given axis were omitted. According to | |
| * Paper I, if any CDi_ja keywords at all are given in a FITS header then those | |
| * not given default to zero. This results in a singular matrix with an | |
| * intersecting row and column of zeros. | |
| * | |
| * Given and returned: | |
| * wcs struct wcsprm* | |
| * Coordinate transformation parameters. | |
| * | |
| * Function return value: | |
| * int Status return value: | |
| * -1: No change required (not an error). | |
| * 0: Success. | |
| * 1: Null wcsprm pointer passed. | |
| * | |
| * | |
| * datfix() - Translate DATE-OBS and derive MJD-OBS or vice versa | |
| * -------------------------------------------------------------- | |
| * datfix() translates the old DATE-OBS date format set in wcsprm::dateobs to | |
| * year-2000 standard form (yyyy-mm-ddThh:mm:ss). | |
| * | |
| * datfix() derives wcsprm::mjdobs from wcsprm::datobs if not already set. | |
| * Alternatively, if mjdobs is set and dateobs isn't, then it derives dateobs | |
| * from it. If both are set but disagree by more than 0.001 day (86.4 seconds) | |
| * then status 5 is returned. Likewise for wcsprm::datebeg and wcsprm::mjdbeg; | |
| * wcsprm::dateavg and wcsprm::mjdavg; and wcsprm::dateend and wcsprm::mjdend. | |
| * | |
| * If neither dateobs nor mjdobs are set, but wcsprm::jepoch (primarily) or | |
| * wcsprm::bepoch is, then both are derived from it. If jepoch and/or bepoch | |
| * are set but disagree with dateobs or mjdobs by more than 0.000002 year | |
| * (63.2 seconds), an informative message is produced. | |
| * | |
| * Given and returned: | |
| * wcs struct wcsprm* | |
| * Coordinate transformation parameters. | |
| * wcsprm::dateobs and/or wcsprm::mjdobs may be changed. | |
| * wcsprm::datebeg and/or wcsprm::mjdbeg may be changed. | |
| * wcsprm::dateavg and/or wcsprm::mjdavg may be changed. | |
| * wcsprm::dateend and/or wcsprm::mjdend may be changed. | |
| * | |
| * Function return value: | |
| * int Status return value: | |
| * -1: No change required (not an error). | |
| * 0: Success. | |
| * 1: Null wcsprm pointer passed. | |
| * 5: Invalid parameter value. | |
| * | |
| * For returns > 1, a detailed error message is set in | |
| * wcsprm::err if enabled, see wcserr_enable(). | |
| * | |
| * Notes: | |
| * The MJD algorithms used by datfix() are from D.A. Hatcher, 1984, QJRAS, | |
| * 25, 53-55, as modified by P.T. Wallace for use in SLALIB subroutines CLDJ | |
| * and DJCL. | |
| * | |
| * | |
| * obsfix() - complete the OBSGEO-[XYZLBH] vector of observatory coordinates | |
| * ------------------------------------------------------------------------- | |
| * obsfix() completes the wcsprm::obsgeo vector of observatory coordinates. | |
| * That is, if only the (x,y,z) Cartesian coordinate triplet or the (l,b,h) | |
| * geodetic coordinate triplet are set, then it derives the other triplet from | |
| * it. If both triplets are set, then it checks for consistency at the level | |
| * of 1 metre. | |
| * | |
| * Given: | |
| * ctrl int Flag that controls behaviour if one triplet is | |
| * defined and the other is only partially defined: | |
| * 0: Reset only the undefined elements of an | |
| * incomplete coordinate triplet. | |
| * 1: Reset all elements of an incomplete triplet. | |
| * 2: Don't make any changes, check for consistency | |
| * only. Returns an error if either of the two | |
| * triplets is incomplete. | |
| * | |
| * Given and returned: | |
| * wcs struct wcsprm* | |
| * Coordinate transformation parameters. | |
| * wcsprm::obsgeo may be changed. | |
| * | |
| * Function return value: | |
| * int Status return value: | |
| * -1: No change required (not an error). | |
| * 0: Success. | |
| * 1: Null wcsprm pointer passed. | |
| * 5: Invalid parameter value. | |
| * | |
| * For returns > 1, a detailed error message is set in | |
| * wcsprm::err if enabled, see wcserr_enable(). | |
| * | |
| * Notes: | |
| * 1: While the International Terrestrial Reference System (ITRS) is based | |
| * solely on Cartesian coordinates, it recommends the use of the GRS80 | |
| * ellipsoid in converting to geodetic coordinates. However, while WCS | |
| * Paper III recommends ITRS Cartesian coordinates, Paper VII prescribes | |
| * the use of the IAU(1976) ellipsoid for geodetic coordinates, and | |
| * consequently that is what is used here. | |
| * | |
| * 2: For reference, parameters of commonly used global reference ellipsoids: | |
| * | |
| = a (m) 1/f Standard | |
| = --------- ------------- -------------------------------- | |
| = 6378140 298.2577 IAU(1976) | |
| = 6378137 298.257222101 GRS80 | |
| = 6378137 298.257223563 WGS84 | |
| = 6378136 298.257 IERS(1989) | |
| = 6378136.6 298.25642 IERS(2003,2010), IAU(2009/2012) | |
| * | |
| * where f = (a - b) / a is the flattening, and a and b are the semi-major | |
| * and semi-minor radii in metres. | |
| * | |
| * 3: The transformation from geodetic (lng,lat,hgt) to Cartesian (x,y,z) is | |
| * | |
| = x = (n + hgt)*coslng*coslat, | |
| = y = (n + hgt)*sinlng*coslat, | |
| = z = (n*(1.0 - e^2) + hgt)*sinlat, | |
| * | |
| * where the "prime vertical radius", n, is a function of latitude | |
| * | |
| = n = a / sqrt(1 - (e*sinlat)^2), | |
| * | |
| * and a, the equatorial radius, and e^2 = (2 - f)*f, the (first) | |
| * eccentricity of the ellipsoid, are constants. obsfix() inverts these | |
| * iteratively by writing | |
| * | |
| = x = rho*coslng*coslat, | |
| = y = rho*sinlng*coslat, | |
| = zeta = rho*sinlat, | |
| * | |
| * where | |
| * | |
| = rho = n + hgt, | |
| = = sqrt(x^2 + y^2 + zeta^2), | |
| = zeta = z / (1 - n*e^2/rho), | |
| * | |
| * and iterating over the value of zeta. Since e is small, a good first | |
| * approximation is given by zeta = z. | |
| * | |
| * | |
| * unitfix() - Correct aberrant CUNITia keyvalues | |
| * ---------------------------------------------- | |
| * unitfix() applies wcsutrn() to translate non-standard CUNITia keyvalues, | |
| * e.g. 'DEG' -> 'deg', also stripping off unnecessary whitespace. | |
| * | |
| * Given: | |
| * ctrl int Do potentially unsafe translations described in the | |
| * usage notes to wcsutrn(). | |
| * | |
| * Given and returned: | |
| * wcs struct wcsprm* | |
| * Coordinate transformation parameters. | |
| * | |
| * Function return value: | |
| * int Status return value: | |
| * -1: No change required (not an error). | |
| * 0: Success (an alias was applied). | |
| * 1: Null wcsprm pointer passed. | |
| * | |
| * When units are translated (i.e. status 0), status -2 | |
| * is set in the wcserr struct to allow an informative | |
| * message to be returned. | |
| * | |
| * | |
| * spcfix() - Translate AIPS-convention spectral types | |
| * --------------------------------------------------- | |
| * spcfix() translates AIPS-convention spectral coordinate types, | |
| * '{FREQ,FELO,VELO}-{LSR,HEL,OBS}' (e.g. 'FREQ-OBS', 'FELO-HEL', 'VELO-LSR') | |
| * set in wcsprm::ctype[], subject to VELREF set in wcsprm::velref. | |
| * | |
| * Note that if wcs::specsys is already set then it will not be overridden. | |
| * | |
| * Given and returned: | |
| * wcs struct wcsprm* | |
| * Coordinate transformation parameters. wcsprm::ctype[] | |
| * and/or wcsprm::specsys may be changed. | |
| * | |
| * Function return value: | |
| * int Status return value: | |
| * -1: No change required (not an error). | |
| * 0: Success. | |
| * 1: Null wcsprm pointer passed. | |
| * 2: Memory allocation failed. | |
| * 3: Linear transformation matrix is singular. | |
| * 4: Inconsistent or unrecognized coordinate axis | |
| * types. | |
| * 5: Invalid parameter value. | |
| * 6: Invalid coordinate transformation parameters. | |
| * 7: Ill-conditioned coordinate transformation | |
| * parameters. | |
| * | |
| * For returns > 1, a detailed error message is set in | |
| * wcsprm::err if enabled, see wcserr_enable(). | |
| * | |
| * | |
| * celfix() - Translate AIPS-convention celestial projection types | |
| * --------------------------------------------------------------- | |
| * celfix() translates AIPS-convention celestial projection types, NCP and | |
| * GLS, set in the ctype[] member of the wcsprm struct. | |
| * | |
| * Two additional pv[] keyvalues are created when translating NCP, and three | |
| * are created when translating GLS with non-zero reference point. If the pv[] | |
| * array was initially allocated by wcsini() then the array will be expanded if | |
| * necessary. Otherwise, error 2 will be returned if sufficient empty slots | |
| * are not already available for use. | |
| * | |
| * Given and returned: | |
| * wcs struct wcsprm* | |
| * Coordinate transformation parameters. wcsprm::ctype[] | |
| * and/or wcsprm::pv[] may be changed. | |
| * | |
| * Function return value: | |
| * int Status return value: | |
| * -1: No change required (not an error). | |
| * 0: Success. | |
| * 1: Null wcsprm pointer passed. | |
| * 2: Memory allocation failed. | |
| * 3: Linear transformation matrix is singular. | |
| * 4: Inconsistent or unrecognized coordinate axis | |
| * types. | |
| * 5: Invalid parameter value. | |
| * 6: Invalid coordinate transformation parameters. | |
| * 7: Ill-conditioned coordinate transformation | |
| * parameters. | |
| * | |
| * For returns > 1, a detailed error message is set in | |
| * wcsprm::err if enabled, see wcserr_enable(). | |
| * | |
| * | |
| * cylfix() - Fix malformed cylindrical projections | |
| * ------------------------------------------------ | |
| * cylfix() fixes WCS keyvalues for malformed cylindrical projections that | |
| * suffer from the problem described in Sect. 7.3.4 of Paper I. | |
| * | |
| * Given: | |
| * naxis const int [] | |
| * Image axis lengths. | |
| * | |
| * Given and returned: | |
| * wcs struct wcsprm* | |
| * Coordinate transformation parameters. | |
| * | |
| * Function return value: | |
| * int Status return value: | |
| * -1: No change required (not an error). | |
| * 0: Success. | |
| * 1: Null wcsprm pointer passed. | |
| * 2: Memory allocation failed. | |
| * 3: Linear transformation matrix is singular. | |
| * 4: Inconsistent or unrecognized coordinate axis | |
| * types. | |
| * 5: Invalid parameter value. | |
| * 6: Invalid coordinate transformation parameters. | |
| * 7: Ill-conditioned coordinate transformation | |
| * parameters. | |
| * 8: All of the corner pixel coordinates are invalid. | |
| * 9: Could not determine reference pixel coordinate. | |
| * 10: Could not determine reference pixel value. | |
| * | |
| * For returns > 1, a detailed error message is set in | |
| * wcsprm::err if enabled, see wcserr_enable(). | |
| * | |
| * | |
| * Global variable: const char *wcsfix_errmsg[] - Status return messages | |
| * --------------------------------------------------------------------- | |
| * Error messages to match the status value returned from each function. | |
| * | |
| *===========================================================================*/ | |
| extern "C" { | |
| extern const char *wcsfix_errmsg[]; | |
| enum wcsfix_errmsg_enum { | |
| FIXERR_OBSGEO_FIX = -5, /* Observatory coordinates amended. */ | |
| FIXERR_DATE_FIX = -4, /* Date string reformatted. */ | |
| FIXERR_SPC_UPDATE = -3, /* Spectral axis type modified. */ | |
| FIXERR_UNITS_ALIAS = -2, /* Units alias translation. */ | |
| FIXERR_NO_CHANGE = -1, /* No change. */ | |
| FIXERR_SUCCESS = 0, /* Success. */ | |
| FIXERR_NULL_POINTER = 1, /* Null wcsprm pointer passed. */ | |
| FIXERR_MEMORY = 2, /* Memory allocation failed. */ | |
| FIXERR_SINGULAR_MTX = 3, /* Linear transformation matrix is | |
| singular. */ | |
| FIXERR_BAD_CTYPE = 4, /* Inconsistent or unrecognized coordinate | |
| axis types. */ | |
| FIXERR_BAD_PARAM = 5, /* Invalid parameter value. */ | |
| FIXERR_BAD_COORD_TRANS = 6, /* Invalid coordinate transformation | |
| parameters. */ | |
| FIXERR_ILL_COORD_TRANS = 7, /* Ill-conditioned coordinate transformation | |
| parameters. */ | |
| FIXERR_BAD_CORNER_PIX = 8, /* All of the corner pixel coordinates are | |
| invalid. */ | |
| FIXERR_NO_REF_PIX_COORD = 9, /* Could not determine reference pixel | |
| coordinate. */ | |
| FIXERR_NO_REF_PIX_VAL = 10 /* Could not determine reference pixel | |
| value. */ | |
| }; | |
| int wcsfix(int ctrl, const int naxis[], struct wcsprm *wcs, int stat[]); | |
| int wcsfixi(int ctrl, const int naxis[], struct wcsprm *wcs, int stat[], | |
| struct wcserr info[]); | |
| int cdfix(struct wcsprm *wcs); | |
| int datfix(struct wcsprm *wcs); | |
| int obsfix(int ctrl, struct wcsprm *wcs); | |
| int unitfix(int ctrl, struct wcsprm *wcs); | |
| int spcfix(struct wcsprm *wcs); | |
| int celfix(struct wcsprm *wcs); | |
| int cylfix(const int naxis[], struct wcsprm *wcs); | |
| } | |