#include "prj.h"

Data Structures
struct	celprm
	Celestial transformation parameters. More...

Macros
#define	CELLEN (sizeof(struct celprm)/sizeof(int))
	Size of the celprm struct in int units. More...

#define	celini_errmsg cel_errmsg
	Deprecated. More...

#define	celprt_errmsg cel_errmsg
	Deprecated. More...

#define	celset_errmsg cel_errmsg
	Deprecated. More...

#define	celx2s_errmsg cel_errmsg
	Deprecated. More...

#define	cels2x_errmsg cel_errmsg
	Deprecated. More...

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. More...

int	celfree (struct celprm *cel)
	Destructor for the celprm struct. More...

int	celprt (const struct celprm *cel)
	Print routine for the celprm struct. More...

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

int	celset (struct celprm *cel)
	Setup routine for the celprm struct. More...

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. More...

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. More...

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, 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

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

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

#define celini_errmsg cel_errmsg

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

#define celprt_errmsg cel_errmsg

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

#define celset_errmsg cel_errmsg

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

#define celx2s_errmsg cel_errmsg

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

#define cels2x_errmsg cel_errmsg

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

Enumeration Type Documentation

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

int celini ( struct celprm * cel )

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

Parameters

[out] cel Celestial transformation parameters.

Returns

Status return value:

0: Success.
1: Null celprm pointer passed.

int celfree ( struct celprm * cel )

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

Parameters

[in] cel Celestial transformation parameters.

Returns

Status return value:

0: Success.
1: Null celprm pointer passed.

int celprt ( const struct celprm * cel )

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

Parameters

[in] cel Celestial transformation parameters.

Returns

Status return value:

0: Success.
1: Null celprm pointer passed.

celperr() - 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]	cel	Coordinate transformation parameters.
[in]	prefix	If non-NULL, each output line will be prefixed with this string.

Returns

Status return value:

0: Success.
1: Null celprm pointer passed.

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

int celset ( struct celprm * cel )

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] cel Celestial 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().

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[]
	)

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

Parameters

[in,out]	cel	Celestial transformation parameters.
[in]	nx,ny	Vector lengths.
[in]	sxy,sll	Vector strides.
[in]	x,y	Projected coordinates in pseudo "degrees".
[out]	phi,theta	Longitude and latitude $(\phi,\theta)$ in the native coordinate system of the projection [deg].
[out]	lng,lat	Celestial longitude and latitude $(\alpha,\delta)$ of the projected point [deg].
[out]	stat	Status return value for each vector element: 0: Success. 1: Invalid value of .

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 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().

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[]
	)

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

Parameters

[in,out]	cel	Celestial transformation parameters.
[in]	nlng,nlat	Vector lengths.
[in]	sll,sxy	Vector strides.
[in]	lng,lat	Celestial longitude and latitude $(\alpha,\delta)$ of the projected point [deg].
[out]	phi,theta	Longitude and latitude $(\phi,\theta)$ in the native coordinate system of the projection [deg].
[out]	x,y	Projected coordinates in pseudo "degrees".
[out]	stat	Status 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

const char* cel_errmsg[]

Data Structures

Macros

Enumerations

Functions

Variables

Detailed Description

Macro Definition Documentation

Enumeration Type Documentation

Function Documentation

Variable Documentation