| /*============================================================================ | |
| 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: log.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 log routines | |
| * --------------------------- | |
| * Routines in this suite implement the part of the FITS World Coordinate | |
| * System (WCS) standard that deals with logarithmic coordinates, as described | |
| * in | |
| * | |
| * "Representations of world coordinates in FITS", | |
| * Greisen, E.W., & Calabretta, M.R. 2002, A&A, 395, 1061 (WCS Paper I) | |
| * | |
| * "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) | |
| * | |
| * These routines define methods to be used for computing logarithmic world | |
| * coordinates from intermediate world coordinates (a linear transformation of | |
| * image pixel coordinates), and vice versa. | |
| * | |
| * logx2s() and logs2x() implement the WCS logarithmic coordinate | |
| * transformations. | |
| * | |
| * Argument checking: | |
| * ------------------ | |
| * The input log-coordinate values are only checked for values that would | |
| * result in floating point exceptions and the same is true for the | |
| * log-coordinate reference value. | |
| * | |
| * Accuracy: | |
| * --------- | |
| * No warranty is given for the accuracy of these routines (refer to the | |
| * copyright notice); intending users must satisfy for themselves their | |
| * adequacy for the intended purpose. However, closure effectively to within | |
| * double precision rounding error was demonstrated by test routine tlog.c | |
| * which accompanies this software. | |
| * | |
| * | |
| * logx2s() - Transform to logarithmic coordinates | |
| * ----------------------------------------------- | |
| * logx2s() transforms intermediate world coordinates to logarithmic | |
| * coordinates. | |
| * | |
| * Given and returned: | |
| * crval double Log-coordinate reference value (CRVALia). | |
| * | |
| * Given: | |
| * nx int Vector length. | |
| * | |
| * sx int Vector stride. | |
| * | |
| * slogc int Vector stride. | |
| * | |
| * x const double[] | |
| * Intermediate world coordinates, in SI units. | |
| * | |
| * Returned: | |
| * logc double[] Logarithmic coordinates, in SI units. | |
| * | |
| * stat int[] Status return value status for each vector element: | |
| * 0: Success. | |
| * | |
| * Function return value: | |
| * int Status return value: | |
| * 0: Success. | |
| * 2: Invalid log-coordinate reference value. | |
| * | |
| * | |
| * logs2x() - Transform logarithmic coordinates | |
| * -------------------------------------------- | |
| * logs2x() transforms logarithmic world coordinates to intermediate world | |
| * coordinates. | |
| * | |
| * Given and returned: | |
| * crval double Log-coordinate reference value (CRVALia). | |
| * | |
| * Given: | |
| * nlogc int Vector length. | |
| * | |
| * slogc int Vector stride. | |
| * | |
| * sx int Vector stride. | |
| * | |
| * logc const double[] | |
| * Logarithmic coordinates, in SI units. | |
| * | |
| * Returned: | |
| * x double[] Intermediate world coordinates, in SI units. | |
| * | |
| * stat int[] Status return value status for each vector element: | |
| * 0: Success. | |
| * 1: Invalid value of logc. | |
| * | |
| * Function return value: | |
| * int Status return value: | |
| * 0: Success. | |
| * 2: Invalid log-coordinate reference value. | |
| * 4: One or more of the world-coordinate values | |
| * are incorrect, as indicated by the stat vector. | |
| * | |
| * | |
| * Global variable: const char *log_errmsg[] - Status return messages | |
| * ------------------------------------------------------------------ | |
| * Error messages to match the status value returned from each function. | |
| * | |
| *===========================================================================*/ | |
| extern "C" { | |
| extern const char *log_errmsg[]; | |
| enum log_errmsg_enum { | |
| LOGERR_SUCCESS = 0, /* Success. */ | |
| LOGERR_NULL_POINTER = 1, /* Null pointer passed. */ | |
| LOGERR_BAD_LOG_REF_VAL = 2, /* Invalid log-coordinate reference value. */ | |
| LOGERR_BAD_X = 3, /* One or more of the x coordinates were | |
| invalid. */ | |
| LOGERR_BAD_WORLD = 4 /* One or more of the world coordinates were | |
| invalid. */ | |
| }; | |
| int logx2s(double crval, int nx, int sx, int slogc, const double x[], | |
| double logc[], int stat[]); | |
| int logs2x(double crval, int nlogc, int slogc, int sx, const double logc[], | |
| double x[], int stat[]); | |
| } | |