WCSLIB 8.2.2
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Data Structures | Macros | Enumerations | Functions | Variables
cel.h File Reference
#include "prj.h"

Go to the source code of this file.

Data Structures

struct  celprm
 Celestial transformation parameters. More...
 

Macros

#define CELLEN   (sizeof(struct celprm)/sizeof(int))
 Size of the celprm struct in int units.
 
#define celini_errmsg   cel_errmsg
 Deprecated.
 
#define celprt_errmsg   cel_errmsg
 Deprecated.
 
#define celset_errmsg   cel_errmsg
 Deprecated.
 
#define celx2s_errmsg   cel_errmsg
 Deprecated.
 
#define cels2x_errmsg   cel_errmsg
 Deprecated.
 

Enumerations

enum  cel_errmsg_enum {
  CELERR_SUCCESS = 0 , CELERR_NULL_POINTER = 1 , CELERR_BAD_PARAM = 2 , CELERR_BAD_COORD_TRANS = 3 ,
  CELERR_ILL_COORD_TRANS = 4 , CELERR_BAD_PIX = 5 , CELERR_BAD_WORLD = 6
}
 

Functions

int celini (struct celprm *cel)
 Default constructor for the celprm struct.
 
int celfree (struct celprm *cel)
 Destructor for the celprm struct.
 
int celsize (const struct celprm *cel, int sizes[2])
 Compute the size of a celprm struct.
 
int celprt (const struct celprm *cel)
 Print routine for the celprm struct.
 
int celperr (const struct celprm *cel, const char *prefix)
 Print error messages from a celprm struct.
 
int celset (struct celprm *cel)
 Setup routine for the celprm struct.
 
int celx2s (struct celprm *cel, int nx, int ny, int sxy, int sll, const double x[], const double y[], double phi[], double theta[], double lng[], double lat[], int stat[])
 Pixel-to-world celestial transformation.
 
int cels2x (struct celprm *cel, int nlng, int nlat, int sll, int sxy, const double lng[], const double lat[], double phi[], double theta[], double x[], double y[], int stat[])
 World-to-pixel celestial transformation.
 

Variables

const char * cel_errmsg []
 

Detailed Description

Routines in this suite implement the part of the FITS World Coordinate System (WCS) standard that deals with celestial 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 celestial coordinates in FITS",
Calabretta, M.R., & Greisen, E.W. 2002, A&A, 395, 1077 (WCS Paper II)

These routines define methods to be used for computing celestial world coordinates from intermediate world coordinates (a linear transformation of image pixel coordinates), and vice versa. They are based on the celprm struct which contains all information needed for the computations. This struct contains some elements that must be set by the user, and others that are maintained by these routines, somewhat like a C++ class but with no encapsulation.

Routine celini() is provided to initialize the celprm struct with default values, celfree() reclaims any memory that may have been allocated to store an error message, celsize() computes its total size including allocated memory, and celprt() prints its contents.

celperr() prints the error message(s), if any, stored in a celprm struct and the prjprm struct that it contains.

A setup routine, celset(), computes intermediate values in the celprm struct from parameters in it that were supplied by the user. The struct always needs to be set up by celset() but it need not be called explicitly - refer to the explanation of celprm::flag.

celx2s() and cels2x() implement the WCS celestial coordinate transformations. In fact, they are high level driver routines for the lower level spherical coordinate rotation and projection routines described in sph.h and prj.h.

Macro Definition Documentation

◆ CELLEN

#define CELLEN   (sizeof(struct celprm)/sizeof(int))

Size of the celprm struct in int units.

Size of the celprm struct in int units, used by the Fortran wrappers.

◆ celini_errmsg

#define celini_errmsg   cel_errmsg

Deprecated.

Deprecated:
Added for backwards compatibility, use cel_errmsg directly now instead.

◆ celprt_errmsg

#define celprt_errmsg   cel_errmsg

Deprecated.

Deprecated:
Added for backwards compatibility, use cel_errmsg directly now instead.

◆ celset_errmsg

#define celset_errmsg   cel_errmsg

Deprecated.

Deprecated:
Added for backwards compatibility, use cel_errmsg directly now instead.

◆ celx2s_errmsg

#define celx2s_errmsg   cel_errmsg

Deprecated.

Deprecated:
Added for backwards compatibility, use cel_errmsg directly now instead.

◆ cels2x_errmsg

#define cels2x_errmsg   cel_errmsg

Deprecated.

Deprecated:
Added for backwards compatibility, use cel_errmsg directly now instead.

Enumeration Type Documentation

◆ cel_errmsg_enum

enum cel_errmsg_enum
Enumerator
CELERR_SUCCESS 
CELERR_NULL_POINTER 
CELERR_BAD_PARAM 
CELERR_BAD_COORD_TRANS 
CELERR_ILL_COORD_TRANS 
CELERR_BAD_PIX 
CELERR_BAD_WORLD 

Function Documentation

◆ celini()

int celini ( struct celprm *  cel)

Default constructor for the celprm struct.

celini() sets all members of a celprm struct to default values. It should be used to initialize every celprm struct.

PLEASE NOTE: If the celprm struct has already been initialized, then before reinitializing, it celfree() should be used to free any memory that may have been allocated to store an error message. A memory leak may otherwise result.

Parameters
[out]celCelestial transformation parameters.
Returns
Status return value:
  • 0: Success.
  • 1: Null celprm pointer passed.

◆ celfree()

int celfree ( struct celprm *  cel)

Destructor for the celprm struct.

celfree() frees any memory that may have been allocated to store an error message in the celprm struct.

Parameters
[in]celCelestial transformation parameters.
Returns
Status return value:
  • 0: Success.
  • 1: Null celprm pointer passed.

◆ celsize()

int celsize ( const struct celprm *  cel,
int  sizes[2] 
)

Compute the size of a celprm struct.

celsize() computes the full size of a celprm struct, including allocated memory.

Parameters
[in]celCelestial transformation parameters.
If NULL, the base size of the struct and the allocated size are both set to zero.
[out]sizesThe first element is the base size of the struct as returned by sizeof(struct celprm). The second element is the total allocated size, in bytes. This figure includes memory allocated for the constituent struct, celprm::err.
It is not an error for the struct not to have been set up via celset().
Returns
Status return value:
  • 0: Success.

◆ celprt()

int celprt ( const struct celprm *  cel)

Print routine for the celprm struct.

celprt() prints the contents of a celprm struct using wcsprintf(). Mainly intended for diagnostic purposes.

Parameters
[in]celCelestial transformation parameters.
Returns
Status return value:
  • 0: Success.
  • 1: Null celprm pointer passed.

◆ celperr()

int celperr ( const struct celprm *  cel,
const char *  prefix 
)

Print error messages from a celprm struct.

celperr() prints the error message(s), if any, stored in a celprm struct and the prjprm struct that it contains. If there are no errors then nothing is printed. It uses wcserr_prt(), q.v.

Parameters
[in]celCoordinate transformation parameters.
[in]prefixIf non-NULL, each output line will be prefixed with this string.
Returns
Status return value:
  • 0: Success.
  • 1: Null celprm pointer passed.

◆ celset()

int celset ( struct celprm *  cel)

Setup routine for the celprm struct.

celset() sets up a celprm struct according to information supplied within it.

Note that this routine need not be called directly; it will be invoked by celx2s() and cels2x() if celprm::flag is anything other than a predefined magic value.

Parameters
[in,out]celCelestial transformation parameters.
Returns
Status return value:
  • 0: Success.
  • 1: Null celprm pointer passed.
  • 2: Invalid projection parameters.
  • 3: Invalid coordinate transformation parameters.
  • 4: Ill-conditioned coordinate transformation parameters.
For returns > 1, a detailed error message is set in celprm::err if enabled, see wcserr_enable().

◆ celx2s()

int celx2s ( struct celprm *  cel,
int  nx,
int  ny,
int  sxy,
int  sll,
const double  x[],
const double  y[],
double  phi[],
double  theta[],
double  lng[],
double  lat[],
int  stat[] 
)

Pixel-to-world celestial transformation.

celx2s() transforms $(x,y)$ coordinates in the plane of projection to celestial coordinates $(\alpha,\delta)$.

Parameters
[in,out]celCelestial transformation parameters.
[in]nx,nyVector lengths.
[in]sxy,sllVector strides.
[in]x,yProjected coordinates in pseudo "degrees".
[out]phi,thetaLongitude and latitude $(\phi,\theta)$ in the native coordinate system of the projection [deg].
[out]lng,latCelestial longitude and latitude $(\alpha,\delta)$ of the projected point [deg].
[out]statStatus return value for each vector element:
  • 0: Success.
  • 1: Invalid value of $(x,y)$.
Returns
Status return value:
  • 0: Success.
  • 1: Null celprm pointer passed.
  • 2: Invalid projection parameters.
  • 3: Invalid coordinate transformation parameters.
  • 4: Ill-conditioned coordinate transformation parameters.
  • 5: One or more of the $(x,y)$ coordinates were invalid, as indicated by the stat vector.
For returns > 1, a detailed error message is set in celprm::err if enabled, see wcserr_enable().

◆ cels2x()

int cels2x ( struct celprm *  cel,
int  nlng,
int  nlat,
int  sll,
int  sxy,
const double  lng[],
const double  lat[],
double  phi[],
double  theta[],
double  x[],
double  y[],
int  stat[] 
)

World-to-pixel celestial transformation.

cels2x() transforms celestial coordinates $(\alpha,\delta)$ to $(x,y)$ coordinates in the plane of projection.

Parameters
[in,out]celCelestial transformation parameters.
[in]nlng,nlatVector lengths.
[in]sll,sxyVector strides.
[in]lng,latCelestial longitude and latitude $(\alpha,\delta)$ of the projected point [deg].
[out]phi,thetaLongitude and latitude $(\phi,\theta)$ in the native coordinate system of the projection [deg].
[out]x,yProjected coordinates in pseudo "degrees".
[out]statStatus return value for each vector element:
  • 0: Success.
  • 1: Invalid value of $(\alpha,\delta)$.
Returns
Status return value:
  • 0: Success.
  • 1: Null celprm pointer passed.
  • 2: Invalid projection parameters.
  • 3: Invalid coordinate transformation parameters.
  • 4: Ill-conditioned coordinate transformation parameters.
  • 6: One or more of the $(\alpha,\delta)$ coordinates were invalid, as indicated by the stat vector.
For returns > 1, a detailed error message is set in celprm::err if enabled, see wcserr_enable().

Variable Documentation

◆ cel_errmsg

const char* cel_errmsg[]
extern
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