WCSLIB: wcsfix.h Source File

WCSLIB 8.9

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wcsfix.h
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1/*============================================================================
2 WCSLIB 8.9 - an implementation of the FITS WCS standard.
3 Copyright (C) 1995-2026, Mark Calabretta
4
5 This file is part of WCSLIB.
6
7 WCSLIB is free software: you can redistribute it and/or modify it under the
8 terms of the GNU Lesser General Public License as published by the Free
9 Software Foundation, either version 3 of the License, or (at your option)
10 any later version.
11
12 WCSLIB is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
14 FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for
15 more details.
16
17 You should have received a copy of the GNU Lesser General Public License
18 along with WCSLIB. If not, see http://www.gnu.org/licenses.
19
20 Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
21 http://www.atnf.csiro.au/computing/software/wcs
22 $Id: wcsfix.h,v 8.9 2026/06/18 13:00:03 mcalabre Exp $
23*=============================================================================
24*
25* WCSLIB 8.9 - C routines that implement the FITS World Coordinate System
26* (WCS) standard. Refer to the README file provided with WCSLIB for an
27* overview of the library.
28*
29*
30* Summary of the wcsfix routines
31* ------------------------------
32* Routines in this suite identify and translate various forms of construct
33* known to occur in FITS headers that violate the FITS World Coordinate System
34* (WCS) standard described in
35*
36= "Representations of world coordinates in FITS",
37= Greisen, E.W., & Calabretta, M.R. 2002, A&A, 395, 1061 (WCS Paper I)
38=
39= "Representations of celestial coordinates in FITS",
40= Calabretta, M.R., & Greisen, E.W. 2002, A&A, 395, 1077 (WCS Paper II)
41=
42= "Representations of spectral coordinates in FITS",
43= Greisen, E.W., Calabretta, M.R., Valdes, F.G., & Allen, S.L.
44= 2006, A&A, 446, 747 (WCS Paper III)
45=
46= "Representations of time coordinates in FITS -
47= Time and relative dimension in space",
48= Rots, A.H., Bunclark, P.S., Calabretta, M.R., Allen, S.L.,
49= Manchester, R.N., & Thompson, W.T. 2015, A&A, 574, A36 (WCS Paper VII)
50*
51* Repairs effected by these routines range from the translation of
52* non-standard values for standard WCS keywords, to the repair of malformed
53* coordinate representations. Some routines are also provided to check the
54* consistency of pairs of keyvalues that define the same measure in two
55* different ways, for example, as a date and an MJD.
56*
57* A separate routine, wcspcx(), "regularizes" the linear transformation matrix
58* component (PCi_j) of the coordinate transformation to make it more human-
59* readable. Where a coordinate description was constructed from CDi_j, it
60* decomposes it into PCi_j + CDELTi in a meaningful way. Optionally, it can
61* also diagonalize the PCi_j matrix (as far as possible), i.e. undo a
62* transposition of axes in the intermediate pixel coordinate system.
63*
64* Non-standard keyvalues:
65* -----------------------
66* AIPS-convention celestial projection types, NCP and GLS, and spectral
67* types, 'FREQ-LSR', 'FELO-HEL', etc., set in CTYPEia are translated
68* on-the-fly by wcsset() but without modifying the relevant ctype[], pv[] or
69* specsys members of the wcsprm struct. That is, only the information
70* extracted from ctype[] is translated when wcsset() fills in wcsprm::cel
71* (celprm struct) or wcsprm::spc (spcprm struct).
72*
73* On the other hand, these routines do change the values of wcsprm::ctype[],
74* wcsprm::pv[], wcsprm::specsys and other wcsprm struct members as
75* appropriate to produce the same result as if the FITS header itself had
76* been translated.
77*
78* Auxiliary WCS header information not used directly by WCSLIB may also be
79* translated. For example, the older DATE-OBS date format (wcsprm::dateobs)
80* is recast to year-2000 standard form, and MJD-OBS (wcsprm::mjdobs) will be
81* deduced from it if not already set.
82*
83* Certain combinations of keyvalues that result in malformed coordinate
84* systems, as described in Sect. 7.3.4 of Paper I, may also be repaired.
85* These are handled by cylfix().
86*
87* Non-standard keywords:
88* ----------------------
89* The AIPS-convention CROTAn keywords are recognized as quasi-standard
90* and as such are accomodated by wcsprm::crota[] and translated to
91* wcsprm::pc[][] by wcsset(). These are not dealt with here, nor are any
92* other non-standard keywords since these routines work only on the contents
93* of a wcsprm struct and do not deal with FITS headers per se. In
94* particular, they do not identify or translate CD00i00j, PC00i00j, PROJPn,
95* EPOCH, VELREF or VSOURCEa keywords; this may be done by the FITS WCS
96* header parser supplied with WCSLIB, refer to wcshdr.h.
97*
98* wcsfix() and wcsfixi() apply all of the corrections handled by the following
99* specific functions, which may also be invoked separately:
100*
101* - cdfix(): Sets the diagonal element of the CDi_ja matrix to 1.0 if all
102* CDi_ja keywords associated with a particular axis are omitted.
103*
104* - datfix(): recast an older DATE-OBS date format in dateobs to year-2000
105* standard form. Derive dateref from mjdref if not already set.
106* Alternatively, if dateref is set and mjdref isn't, then derive mjdref
107* from it. If both are set, then check consistency. Likewise for dateobs
108* and mjdobs; datebeg and mjdbeg; dateavg and mjdavg; and dateend and
109* mjdend.
110*
111* - obsfix(): if only one half of obsgeo[] is set, then derive the other
112* half from it. If both halves are set, then check consistency.
113*
114* - unitfix(): translate some commonly used but non-standard unit strings in
115* the CUNITia keyvalues, e.g. 'DEG' -> 'deg'.
116*
117* - spcfix(): translate AIPS-convention spectral types, 'FREQ-LSR',
118* 'FELO-HEL', etc., in ctype[] as set from CTYPEia.
119*
120* - celfix(): translate AIPS-convention celestial projection types, NCP and
121* GLS, in ctype[] as set from CTYPEia.
122*
123* - cylfix(): fixes WCS keyvalues for malformed cylindrical projections that
124* suffer from the problem described in Sect. 7.3.4 of Paper I.
125*
126*
127* wcsfix() - Translate a non-standard WCS struct
128* ----------------------------------------------
129* wcsfix() is identical to wcsfixi(), but lacks the info argument.
130*
131*
132* wcsfixi() - Translate a non-standard WCS struct
133* -----------------------------------------------
134* wcsfixi() applies all of the corrections handled separately by cdfix(),
135* datfix(), obsfix(), unitfix(), spcfix(), celfix(), and cylfix().
136*
137* Given:
138* ctrl int Do potentially unsafe translations of non-standard
139* unit strings as described in the usage notes to
140* wcsutrn().
141*
142* naxis const int []
143* Image axis lengths. If this array pointer is set to
144* zero then cylfix() will not be invoked.
145*
146* Given and returned:
147* wcs struct wcsprm*
148* Coordinate transformation parameters.
149*
150* Returned:
151* stat int [NWCSFIX]
152* Status returns from each of the functions. Use the
153* preprocessor macros NWCSFIX to dimension this vector
154* and CDFIX, DATFIX, OBSFIX, UNITFIX, SPCFIX, CELFIX,
155* and CYLFIX to access its elements. A status value
156* of -2 is set for functions that were not invoked.
157*
158* info struct wcserr [NWCSFIX]
159* Status messages from each of the functions. Use the
160* preprocessor macros NWCSFIX to dimension this vector
161* and CDFIX, DATFIX, OBSFIX, UNITFIX, SPCFIX, CELFIX,
162* and CYLFIX to access its elements.
163*
164* Note that the memory allocated by wcsfixi() for the
165* message in each wcserr struct (wcserr::msg, if
166* non-zero) must be freed by the user. See
167* wcsdealloc().
168*
169* Function return value:
170* int Status return value:
171* 0: Success.
172* 1: One or more of the translation functions
173* returned an error.
174*
175*
176* cdfix() - Fix erroneously omitted CDi_ja keywords
177* -------------------------------------------------
178* cdfix() sets the diagonal element of the CDi_ja matrix to unity if all
179* CDi_ja keywords associated with a given axis were omitted. According to WCS
180* Paper I, if any CDi_ja keywords at all are given in a FITS header then those
181* not given default to zero. This results in a singular matrix with an
182* intersecting row and column of zeros.
183*
184* cdfix() is expected to be invoked before wcsset(), which will fail if these
185* errors have not been corrected.
186*
187* Given and returned:
188* wcs struct wcsprm*
189* Coordinate transformation parameters.
190*
191* Function return value:
192* int Status return value:
193* -1: No change required (not an error).
194* 0: Success.
195* 1: Null wcsprm pointer passed.
196*
197*
198* datfix() - Translate DATE-OBS and derive MJD-OBS or vice versa
199* --------------------------------------------------------------
200* datfix() translates the old DATE-OBS date format set in wcsprm::dateobs to
201* year-2000 standard form (yyyy-mm-ddThh:mm:ss). It derives wcsprm::dateref
202* from wcsprm::mjdref if not already set. Alternatively, if dateref is set
203* and mjdref isn't, then it derives mjdref from it. If both are set but
204* disagree by more than 0.001 day (86.4 seconds) then an error status is
205* returned. Likewise for wcsprm::dateobs and wcsprm::mjdobs; wcsprm::datebeg
206* and wcsprm::mjdbeg; wcsprm::dateavg and wcsprm::mjdavg; and wcsprm::dateend
207* and wcsprm::mjdend.
208*
209* If neither dateobs nor mjdobs are set, but wcsprm::jepoch (primarily) or
210* wcsprm::bepoch is, then both are derived from it. If jepoch and/or bepoch
211* are set but disagree with dateobs or mjdobs by more than 0.000002 year
212* (63.2 seconds), an informative message is produced.
213*
214* The translations done by datfix() do not affect and are not affected by
215* wcsset().
216*
217* Given and returned:
218* wcs struct wcsprm*
219* Coordinate transformation parameters.
220* wcsprm::dateref and/or wcsprm::mjdref may be changed.
221* wcsprm::dateobs and/or wcsprm::mjdobs may be changed.
222* wcsprm::datebeg and/or wcsprm::mjdbeg may be changed.
223* wcsprm::dateavg and/or wcsprm::mjdavg may be changed.
224* wcsprm::dateend and/or wcsprm::mjdend may be changed.
225*
226* Function return value:
227* int Status return value:
228* -1: No change required (not an error).
229* 0: Success.
230* 1: Null wcsprm pointer passed.
231* 5: Invalid parameter value.
232*
233* For returns >= 0, a detailed message, whether
234* informative or an error message, may be set in
235* wcsprm::err if enabled, see wcserr_enable(), with
236* wcsprm::err.status set to FIXERR_DATE_FIX.
237*
238* Notes:
239* 1: The MJD algorithms used by datfix() are from D.A. Hatcher, 1984, QJRAS,
240* 25, 53-55, as modified by P.T. Wallace for use in SLALIB subroutines
241* CLDJ and DJCL.
242*
243*
244* obsfix() - complete the OBSGEO-[XYZLBH] vector of observatory coordinates
245* -------------------------------------------------------------------------
246* obsfix() completes the wcsprm::obsgeo vector of observatory coordinates.
247* That is, if only the (x,y,z) Cartesian coordinate triplet or the (l,b,h)
248* geodetic coordinate triplet are set, then it derives the other triplet from
249* it. If both triplets are set, then it checks for consistency at the level
250* of 1 metre.
251*
252* The operations done by obsfix() do not affect and are not affected by
253* wcsset().
254*
255* Given:
256* ctrl int Flag that controls behaviour if one triplet is
257* defined and the other is only partially defined:
258* 0: Reset only the undefined elements of an
259* incomplete coordinate triplet.
260* 1: Reset all elements of an incomplete triplet.
261* 2: Don't make any changes, check for consistency
262* only. Returns an error if either of the two
263* triplets is incomplete.
264*
265* Given and returned:
266* wcs struct wcsprm*
267* Coordinate transformation parameters.
268* wcsprm::obsgeo may be changed.
269*
270* Function return value:
271* int Status return value:
272* -1: No change required (not an error).
273* 0: Success.
274* 1: Null wcsprm pointer passed.
275* 5: Invalid parameter value.
276*
277* For returns >= 0, a detailed message, whether
278* informative or an error message, may be set in
279* wcsprm::err if enabled, see wcserr_enable(), with
280* wcsprm::err.status set to FIXERR_OBS_FIX.
281*
282* Notes:
283* 1: While the International Terrestrial Reference System (ITRS) is based
284* solely on Cartesian coordinates, it recommends the use of the GRS80
285* ellipsoid in converting to geodetic coordinates. However, while WCS
286* Paper III recommends ITRS Cartesian coordinates, Paper VII prescribes
287* the use of the IAU(1976) ellipsoid for geodetic coordinates, and
288* consequently that is what is used here.
289*
290* 2: For reference, parameters of commonly used global reference ellipsoids:
291*
292= a (m) 1/f Standard
293= --------- ------------- --------------------------------
294= 6378140 298.2577 IAU(1976)
295= 6378137 298.257222101 GRS80
296= 6378137 298.257223563 WGS84
297= 6378136 298.257 IERS(1989)
298= 6378136.6 298.25642 IERS(2003,2010), IAU(2009/2012)
299*
300* where f = (a - b) / a is the flattening, and a and b are the semi-major
301* and semi-minor radii in metres.
302*
303* 3: The transformation from geodetic (lng,lat,hgt) to Cartesian (x,y,z) is
304*
305= x = (n + hgt)*coslng*coslat,
306= y = (n + hgt)*sinlng*coslat,
307= z = (n*(1.0 - e^2) + hgt)*sinlat,
308*
309* where the "prime vertical radius", n, is a function of latitude
310*
311= n = a / sqrt(1 - (e*sinlat)^2),
312*
313* and a, the equatorial radius, and e^2 = (2 - f)*f, the (first)
314* eccentricity of the ellipsoid, are constants. obsfix() inverts these
315* iteratively by writing
316*
317= x = rho*coslng*coslat,
318= y = rho*sinlng*coslat,
319= zeta = rho*sinlat,
320*
321* where
322*
323= rho = n + hgt,
324= = sqrt(x^2 + y^2 + zeta^2),
325= zeta = z / (1 - n*e^2/rho),
326*
327* and iterating over the value of zeta. Since e is small, a good first
328* approximation is given by zeta = z.
329*
330*
331* unitfix() - Correct aberrant CUNITia keyvalues
332* ----------------------------------------------
333* unitfix() applies wcsutrn() to translate non-standard CUNITia keyvalues,
334* e.g. 'DEG' -> 'deg', also stripping off unnecessary whitespace.
335*
336* unitfix() is expected to be invoked before wcsset(), which will fail if
337* non-standard CUNITia keyvalues have not been translated.
338*
339* Given:
340* ctrl int Do potentially unsafe translations described in the
341* usage notes to wcsutrn().
342*
343* Given and returned:
344* wcs struct wcsprm*
345* Coordinate transformation parameters.
346*
347* Function return value:
348* int Status return value:
349* -1: No change required (not an error).
350* 0: Success (an alias was applied).
351* 1: Null wcsprm pointer passed.
352*
353* When units are translated (i.e. 0 is returned), an
354* informative message is set in wcsprm::err if enabled,
355* see wcserr_enable(), with wcsprm::err.status set to
356* FIXERR_UNITS_ALIAS.
357*
358*
359* spcfix() - Translate AIPS-convention spectral types
360* ---------------------------------------------------
361* spcfix() translates AIPS-convention spectral coordinate types,
362* '{FREQ,FELO,VELO}-{LSR,HEL,OBS}' (e.g. 'FREQ-OBS', 'FELO-HEL', 'VELO-LSR')
363* set in wcsprm::ctype[], subject to VELREF set in wcsprm::velref.
364*
365* Note that if wcs::specsys is already set then it will not be overridden.
366*
367* AIPS-convention spectral types set in CTYPEia are translated on-the-fly by
368* wcsset() but without modifying wcsprm::ctype[] or wcsprm::specsys. That is,
369* only the information extracted from wcsprm::ctype[] is translated when
370* wcsset() fills in wcsprm::spc (spcprm struct). spcfix() modifies
371* wcsprm::ctype[] so that if the header is subsequently written out, e.g. by
372* wcshdo(), then it will contain translated CTYPEia keyvalues.
373*
374* The operations done by spcfix() do not affect and are not affected by
375* wcsset().
376*
377* Given and returned:
378* wcs struct wcsprm*
379* Coordinate transformation parameters. wcsprm::ctype[]
380* and/or wcsprm::specsys may be changed.
381*
382* Function return value:
383* int Status return value:
384* -1: No change required (not an error).
385* 0: Success.
386* 1: Null wcsprm pointer passed.
387* 2: Memory allocation failed.
388* 3: Linear transformation matrix is singular.
389* 4: Inconsistent or unrecognized coordinate axis
390* types.
391* 5: Invalid parameter value.
392* 6: Invalid coordinate transformation parameters.
393* 7: Ill-conditioned coordinate transformation
394* parameters.
395*
396* For returns >= 0, a detailed message, whether
397* informative or an error message, may be set in
398* wcsprm::err if enabled, see wcserr_enable(), with
399* wcsprm::err.status set to FIXERR_SPC_UPDTE.
400*
401*
402* celfix() - Translate AIPS-convention celestial projection types
403* ---------------------------------------------------------------
404* celfix() translates AIPS-convention celestial projection types, NCP and
405* GLS, set in the ctype[] member of the wcsprm struct.
406*
407* Two additional pv[] keyvalues are created when translating NCP, and three
408* are created when translating GLS with non-zero reference point. If the pv[]
409* array was initially allocated by wcsini() then the array will be expanded if
410* necessary. Otherwise, error 2 will be returned if sufficient empty slots
411* are not already available for use.
412*
413* AIPS-convention celestial projection types set in CTYPEia are translated
414* on-the-fly by wcsset() but without modifying wcsprm::ctype[], wcsprm::pv[],
415* or wcsprm::npv. That is, only the information extracted from
416* wcsprm::ctype[] is translated when wcsset() fills in wcsprm::cel (celprm
417* struct). celfix() modifies wcsprm::ctype[], wcsprm::pv[], and wcsprm::npv
418* so that if the header is subsequently written out, e.g. by wcshdo(), then it
419* will contain translated CTYPEia keyvalues and the relevant PVi_ma.
420*
421* The operations done by celfix() do not affect and are not affected by
422* wcsset(). However, it uses information in the wcsprm struct provided by
423* wcsset(), and will invoke it if necessary.
424*
425* Given and returned:
426* wcs struct wcsprm*
427* Coordinate transformation parameters. wcsprm::ctype[]
428* and/or wcsprm::pv[] may be changed.
429*
430* Function return value:
431* int Status return value:
432* -1: No change required (not an error).
433* 0: Success.
434* 1: Null wcsprm pointer passed.
435* 2: Memory allocation failed.
436* 3: Linear transformation matrix is singular.
437* 4: Inconsistent or unrecognized coordinate axis
438* types.
439* 5: Invalid parameter value.
440* 6: Invalid coordinate transformation parameters.
441* 7: Ill-conditioned coordinate transformation
442* parameters.
443*
444* For returns > 1, a detailed error message is set in
445* wcsprm::err if enabled, see wcserr_enable().
446*
447*
448* cylfix() - Fix malformed cylindrical projections
449* ------------------------------------------------
450* cylfix() fixes WCS keyvalues for malformed cylindrical projections that
451* suffer from the problem described in Sect. 7.3.4 of Paper I.
452*
453* cylfix() requires the wcsprm struct to have been set up by wcsset(), and
454* will invoke it if necessary. After modification, the struct is reset on
455* return with an explicit call to wcsset().
456*
457* Given:
458* naxis const int []
459* Image axis lengths.
460*
461* Given and returned:
462* wcs struct wcsprm*
463* Coordinate transformation parameters.
464*
465* Function return value:
466* int Status return value:
467* -1: No change required (not an error).
468* 0: Success.
469* 1: Null wcsprm pointer passed.
470* 2: Memory allocation failed.
471* 3: Linear transformation matrix is singular.
472* 4: Inconsistent or unrecognized coordinate axis
473* types.
474* 5: Invalid parameter value.
475* 6: Invalid coordinate transformation parameters.
476* 7: Ill-conditioned coordinate transformation
477* parameters.
478* 8: All of the corner pixel coordinates are invalid.
479* 9: Could not determine reference pixel coordinate.
480* 10: Could not determine reference pixel value.
481*
482* For returns > 1, a detailed error message is set in
483* wcsprm::err if enabled, see wcserr_enable().
484*
485*
486* wcspcx() - regularize PCi_j
487* ---------------------------
488* wcspcx() "regularizes" the linear transformation matrix component of the
489* coordinate transformation (PCi_ja) to make it more human-readable.
490*
491* Normally, upon encountering a FITS header containing a CDi_ja matrix,
492* wcsset() simply treats it as PCi_ja and sets CDELTia to unity. However,
493* wcspcx() decomposes CDi_ja into PCi_ja and CDELTia in such a way that
494* CDELTia form meaningful scaling parameters. In practice, the residual
495* PCi_ja matrix will often then be orthogonal, i.e. unity, or describing a
496* pure rotation, axis permutation, or reflection, or a combination thereof.
497*
498* The decomposition is based on normalizing the length in the transformed
499* system (i.e. intermediate pixel coordinates) of the orthonormal basis
500* vectors of the pixel coordinate system. This deviates slightly from the
501* prescription given by Eq. (4) of WCS Paper I, namely Sum(j=1,N)(PCi_ja)² = 1,
502* in replacing the sum over j with the sum over i. Consequently, the columns
503* of PCi_ja will consist of unit vectors. In practice, especially in cubes
504* and higher dimensional images, at least some pairs of these unit vectors, if
505* not all, will often be orthogonal or close to orthogonal.
506*
507* The sign of CDELTia is chosen to make the PCi_ja matrix as close to the,
508* possibly permuted, unit matrix as possible, except that where the coordinate
509* description contains a pair of celestial axes, the sign of CDELTia is set
510* negative for the longitude axis and positive for the latitude axis.
511*
512* Optionally, rows of the PCi_ja matrix may also be permuted to diagonalize
513* it as far as possible, thus undoing any transposition of axes in the
514* intermediate pixel coordinate system.
515*
516* If the coordinate description contains a celestial plane, then the angle of
517* rotation of each of the basis vectors associated with the celestial axes is
518* returned. For a pure rotation the two angles should be identical. Any
519* difference between them is a measure of axis skewness.
520*
521* The decomposition is not performed for axes involving a sequent distortion
522* function that is defined in terms of CDi_ja, such as TPV, TNX, or ZPX, which
523* always are. The independent variables of the polynomial are therefore
524* intermediate world coordinates rather than intermediate pixel coordinates.
525* Because sequent distortions are always applied before CDELTia, if CDi_ja was
526* translated to PCi_ja plus CDELTia, then the distortion would be altered
527* unless the polynomial coefficients were also adjusted to account for the
528* change of scale.
529*
530* wcspcx() requires the wcsprm struct to have been set up by wcsset(), and
531* will invoke it if necessary. The wcsprm struct is reset on return with an
532* explicit call to wcsset().
533*
534* Given and returned:
535* wcs struct wcsprm*
536* Coordinate transformation parameters.
537*
538* Given:
539* dopc int If 1, then PCi_ja and CDELTia, as given, will be
540* recomposed according to the above prescription. If 0,
541* the operation is restricted to decomposing CDi_ja.
542*
543* permute int If 1, then after decomposition (or recomposition),
544* permute rows of PCi_ja to make the axes of the
545* intermediate pixel coordinate system match as closely
546* as possible those of the pixel coordinates. That is,
547* make it as close to a diagonal matrix as possible.
548* However, celestial axes are special in always being
549* paired, with the longitude axis preceding the latitude
550* axis.
551*
552* All WCS entities indexed by i, such as CTYPEia,
553* CRVALia, CDELTia, etc., including coordinate lookup
554* tables, will also be permuted as necessary to account
555* for the change to PCi_ja. This does not apply to
556* CRPIXja, nor prior distortion functions. These
557* operate on pixel coordinates, which are not affected
558* by the permutation.
559*
560* Returned:
561* rotn double[2] Rotation angle [deg] of each basis vector associated
562* with the celestial axes. For a pure rotation the two
563* angles should be identical. Any difference between
564* them is a measure of axis skewness.
565*
566* May be set to the NULL pointer if this information is
567* not required.
568*
569* Function return value:
570* int Status return value:
571* 0: Success.
572* 1: Null wcsprm pointer passed.
573* 2: Memory allocation failed.
574* 5: CDi_j matrix not used.
575* 6: Sequent distortion function present.
576*
577*
578* Global variable: const char *wcsfix_errmsg[] - Status return messages
579* ---------------------------------------------------------------------
580* Error messages to match the status value returned from each function.
581*
582*===========================================================================*/
583
584#ifndef WCSLIB_WCSFIX
585#define WCSLIB_WCSFIX
586
587#include "wcs.h"
588#include "wcserr.h"
589
590#ifdef __cplusplus
591extern "C" {
592#endif
593
594#define CDFIX 0
595#define DATFIX 1
596#define OBSFIX 2
597#define UNITFIX 3
598#define SPCFIX 4
599#define CELFIX 5
600#define CYLFIX 6
601#define NWCSFIX 7
602
603extern const char *wcsfix_errmsg[];
604#define cylfix_errmsg wcsfix_errmsg
605
606 enum wcsfix_errmsg_enum {
607 FIXERR_OBSGEO_FIX = -5, // Observatory coordinates amended.
608 FIXERR_DATE_FIX = -4, // Date string reformatted.
609 FIXERR_SPC_UPDATE = -3, // Spectral axis type modified.
610 FIXERR_UNITS_ALIAS = -2, // Units alias translation.
611 FIXERR_NO_CHANGE = -1, // No change.
612 FIXERR_SUCCESS = 0, // Success.
613 FIXERR_NULL_POINTER = 1, // Null wcsprm pointer passed.
614 FIXERR_MEMORY = 2, // Memory allocation failed.
615 FIXERR_SINGULAR_MTX = 3, // Linear transformation matrix is singular.
616 FIXERR_BAD_CTYPE = 4, // Inconsistent or unrecognized coordinate
617 // axis types.
618 FIXERR_BAD_PARAM = 5, // Invalid parameter value.
619 FIXERR_BAD_COORD_TRANS = 6, // Invalid coordinate transformation
620 // parameters.
621 FIXERR_ILL_COORD_TRANS = 7, // Ill-conditioned coordinate transformation
622 // parameters.
623 FIXERR_BAD_CORNER_PIX = 8, // All of the corner pixel coordinates are
624 // invalid.
625 FIXERR_NO_REF_PIX_COORD = 9, // Could not determine reference pixel
626 // coordinate.
627 FIXERR_NO_REF_PIX_VAL = 10 // Could not determine reference pixel value.
628};
629
630 int wcsfix(int ctrl, const int naxis[], struct wcsprm *wcs, int stat[]);
631
632 int wcsfixi(int ctrl, const int naxis[], struct wcsprm *wcs, int stat[],
633 struct wcserr info[]);
634
635 int cdfix(struct wcsprm *wcs);
636
637 int datfix(struct wcsprm *wcs);
638
639 int obsfix(int ctrl, struct wcsprm *wcs);
640
641 int unitfix(int ctrl, struct wcsprm *wcs);
642
643 int spcfix(struct wcsprm *wcs);
644
645 int celfix(struct wcsprm *wcs);
646
647 int cylfix(const int naxis[], struct wcsprm *wcs);
648
649 int wcspcx(struct wcsprm *wcs, int dopc, int permute, double rotn[2]);
650
651
652#ifdef __cplusplus
653}
654#endif
655
656#endif // WCSLIB_WCSFIX
wcserr
Error message handling.
Definition wcserr.h:243
wcsprm
Coordinate transformation parameters.
Definition wcs.h:2134
wcs.h
wcserr.h
wcsfix_errmsg_enum
wcsfix_errmsg_enum
Definition wcsfix.h:606
FIXERR_NO_REF_PIX_VAL
@ FIXERR_NO_REF_PIX_VAL
Definition wcsfix.h:627
FIXERR_UNITS_ALIAS
@ FIXERR_UNITS_ALIAS
Definition wcsfix.h:610
FIXERR_OBSGEO_FIX
@ FIXERR_OBSGEO_FIX
Definition wcsfix.h:607
FIXERR_MEMORY
@ FIXERR_MEMORY
Definition wcsfix.h:614
FIXERR_DATE_FIX
@ FIXERR_DATE_FIX
Definition wcsfix.h:608
FIXERR_BAD_PARAM
@ FIXERR_BAD_PARAM
Definition wcsfix.h:618
FIXERR_BAD_CORNER_PIX
@ FIXERR_BAD_CORNER_PIX
Definition wcsfix.h:623
FIXERR_BAD_CTYPE
@ FIXERR_BAD_CTYPE
Definition wcsfix.h:616
FIXERR_BAD_COORD_TRANS
@ FIXERR_BAD_COORD_TRANS
Definition wcsfix.h:619
FIXERR_SPC_UPDATE
@ FIXERR_SPC_UPDATE
Definition wcsfix.h:609
FIXERR_ILL_COORD_TRANS
@ FIXERR_ILL_COORD_TRANS
Definition wcsfix.h:621
FIXERR_SINGULAR_MTX
@ FIXERR_SINGULAR_MTX
Definition wcsfix.h:615
FIXERR_NO_REF_PIX_COORD
@ FIXERR_NO_REF_PIX_COORD
Definition wcsfix.h:625
FIXERR_NO_CHANGE
@ FIXERR_NO_CHANGE
Definition wcsfix.h:611
FIXERR_SUCCESS
@ FIXERR_SUCCESS
Definition wcsfix.h:612
FIXERR_NULL_POINTER
@ FIXERR_NULL_POINTER
Definition wcsfix.h:613
cylfix
int cylfix(const int naxis[], struct wcsprm *wcs)
Fix malformed cylindrical projections.
cdfix
int cdfix(struct wcsprm *wcs)
Fix erroneously omitted CDi_ja keywords.
obsfix
int obsfix(int ctrl, struct wcsprm *wcs)
complete the OBSGEO-[XYZLBH] vector of observatory coordinates.
wcsfixi
int wcsfixi(int ctrl, const int naxis[], struct wcsprm *wcs, int stat[], struct wcserr info[])
Translate a non-standard WCS struct.
datfix
int datfix(struct wcsprm *wcs)
Translate DATE-OBS and derive MJD-OBS or vice versa.
wcspcx
int wcspcx(struct wcsprm *wcs, int dopc, int permute, double rotn[2])
regularize PCi_j.
unitfix
int unitfix(int ctrl, struct wcsprm *wcs)
Correct aberrant CUNITia keyvalues.
wcsfix
int wcsfix(int ctrl, const int naxis[], struct wcsprm *wcs, int stat[])
Translate a non-standard WCS struct.
wcsfix_errmsg
const char * wcsfix_errmsg[]
Status return messages.
celfix
int celfix(struct wcsprm *wcs)
Translate AIPS-convention celestial projection types.
spcfix
int spcfix(struct wcsprm *wcs)
Translate AIPS-convention spectral types.