Functions | |
cpl_error_code | cpl_wcs_convert (const cpl_wcs *wcs, const cpl_matrix *from, cpl_matrix **to, cpl_array **status, cpl_wcs_trans_mode transform) |
Convert between physical and world coordinates. | |
void | cpl_wcs_delete (cpl_wcs *wcs) |
Destroy a WCS structure. | |
const cpl_matrix * | cpl_wcs_get_cd (const cpl_wcs *wcs) |
Accessor to get the CD matrix for a WCS. | |
const cpl_array * | cpl_wcs_get_crpix (const cpl_wcs *wcs) |
Accessor to get the CRPIX vector for a WCS. | |
const cpl_array * | cpl_wcs_get_crval (const cpl_wcs *wcs) |
Accessor to get the CRVAL vector for a WCS. | |
const cpl_array * | cpl_wcs_get_image_dims (const cpl_wcs *wcs) |
Accessor to get the axis lengths of the image associated with a WCS. | |
int | cpl_wcs_get_image_naxis (const cpl_wcs *wcs) |
Accessor to get the dimensionality of the image associated with a WCS. | |
cpl_wcs * | cpl_wcs_new_from_propertylist (const cpl_propertylist *plist) |
Create a wcs structure by parsing a propertylist. | |
cpl_error_code | cpl_wcs_platesol (cpl_propertylist *ilist, cpl_matrix *cel, cpl_matrix *xy, int niter, float thresh, cpl_wcs_platesol_fitmode fitmode, cpl_wcs_platesol_outmode outmode, cpl_propertylist **olist) |
Do a 2d plate solution given physical and celestial coordinates. |
A cpl_wcs is an object containing a pointer to the WCSLIB structure and the physical dimensions of the image from which the WCS was read. The functionality provided includes general transformations between physical and world coordinates as well as a few convenience routines for x,y <=> RA,Dec transformations.
#include "cpl_wcs.h"
cpl_error_code cpl_wcs_convert | ( | const cpl_wcs * | wcs, | |
const cpl_matrix * | from, | |||
cpl_matrix ** | to, | |||
cpl_array ** | status, | |||
cpl_wcs_trans_mode | transform | |||
) |
Convert between physical and world coordinates.
wcs | The input cpl_wcs structure | |
from | The input coordinate matrix | |
to | The output coordinate matrix | |
status | The output status array | |
transform | The transformation mode |
CPL_ERROR_NULL_INPUT | The parameter wcs is a NULL pointer, the parameter from is a NULL pointer or wcs is missing some of its information. |
CPL_ERROR_UNSPECIFIED | No rows or columns in the input matrix, or an unspecified error has occurred in the WCSLIB routine |
CPL_ERROR_UNSUPPORTED_MODE | The input conversion mode is not supported |
CPL_ERROR_NO_WCS | The WCS sub library is not available. |
This function converts between several types of coordinates. These include: -- physical coordinates: The physical location on a detector (i.e. pixel coordinates) -- world coordinates: The real astronomical coordinate system for the observations. This may be spectral, celestial, time, etc. -- standard coordinates: These are an intermediate relative coordinate representation, defined as a distance from a reference point in the natural units of the world coordinate system. Any defined projection geometry will have already been included in the definition of standard coordinates.
The supported conversion modes are: -- CPL_WCS_PHYS2WORLD: Converts input physical to world coordinates -- CPL_WCS_WORLD2PHYS: Converts input world to physical coordinates -- CPL_WCS_WORLD2STD: Converts input world to standard coordinates -- CPL_WCS_PHYS2STD: Converts input physical to standard coordinates The output matrix and status arrays will be allocated here, and thus will need to be freed by the calling routine. The status array is used to flag input coordinates where there has been some sort of failure in the transformation.
void cpl_wcs_delete | ( | cpl_wcs * | wcs | ) |
Destroy a WCS structure.
wcs | The WCS structure to destroy |
CPL_ERROR_NO_WCS | The WCS sub library is not available. |
NULL
, nothing is done and no error is set.
const cpl_matrix* cpl_wcs_get_cd | ( | const cpl_wcs * | wcs | ) |
Accessor to get the CD matrix for a WCS.
wcs | The WCS structure to examine |
CPL_ERROR_NO_WCS | The WCS sub library is not available. |
const cpl_array* cpl_wcs_get_crpix | ( | const cpl_wcs * | wcs | ) |
Accessor to get the CRPIX vector for a WCS.
wcs | The WCS structure to examine |
CPL_ERROR_NO_WCS | The WCS sub library is not available. |
const cpl_array* cpl_wcs_get_crval | ( | const cpl_wcs * | wcs | ) |
Accessor to get the CRVAL vector for a WCS.
wcs | The WCS structure to examine |
CPL_ERROR_NO_WCS | The WCS sub library is not available. |
const cpl_array* cpl_wcs_get_image_dims | ( | const cpl_wcs * | wcs | ) |
Accessor to get the axis lengths of the image associated with a WCS.
wcs | The WCS structure to examine |
CPL_ERROR_NO_WCS | The WCS sub library is not available. |
int cpl_wcs_get_image_naxis | ( | const cpl_wcs * | wcs | ) |
Accessor to get the dimensionality of the image associated with a WCS.
wcs | The WCS structure to examine |
CPL_ERROR_NO_WCS | The WCS sub library is not available. |
cpl_wcs* cpl_wcs_new_from_propertylist | ( | const cpl_propertylist * | plist | ) |
Create a wcs structure by parsing a propertylist.
plist | The input propertylist |
CPL_ERROR_NULL_INPUT | The parameter plist is a NULL pointer. |
CPL_ERROR_TYPE_MISMATCH | NAXIS information in image propertylist is not an integer |
CPL_ERROR_DATA_NOT_FOUND | Error in getting NAXIS information for image propertylists |
CPL_ERROR_UNSPECIFIED | An unspecified error occurred in the WCSLIB routine. |
CPL_ERROR_NO_WCS | The WCS sub library is not available. |
The function allocates memory for a WCS structure. A pointer to the WCSLIB header information is created by parsing the FITS WCS keywords from the header of a file. A few ancillary items are also filled in.
The returned property must be destroyed using the wcs destructor cpl_wcs_delete().
cpl_error_code cpl_wcs_platesol | ( | cpl_propertylist * | ilist, | |
cpl_matrix * | cel, | |||
cpl_matrix * | xy, | |||
int | niter, | |||
float | thresh, | |||
cpl_wcs_platesol_fitmode | fitmode, | |||
cpl_wcs_platesol_outmode | outmode, | |||
cpl_propertylist ** | olist | |||
) |
Do a 2d plate solution given physical and celestial coordinates.
ilist | The input property list containing the first pass WCS | |
cel | The celestial coordinate matrix | |
xy | The physical coordinate matrix | |
niter | The number of fitting iterations | |
thresh | The threshold for the fitting rejection cycle | |
fitmode | The fitting mode (see below) | |
outmode | The output mode (see below) | |
olist | The output propertylist containing the new WCS |
CPL_ERROR_NULL_INPUT | The parameter cel is a NULL pointer, the parameter xy is a NULL pointer or ilist is a NULL pointer. |
CPL_ERROR_UNSPECIFIED | Unable to parse the input propertylist into a proper FITS WCS or there are too few points in the input matrices for a fit. |
CPL_ERROR_INCOMPATIBLE_INPUT | The matrices cel and xy have different sizes. |
CPL_ERROR_UNSUPPORTED_MODE | Either fitmode or outmode are specified incorrectly |
CPL_ERROR_NO_WCS | The WCS sub library is not available. |
This function allows for the following type of fits: -- CPL_WCS_PLATESOL_4: Fit for zero point, 1 scale and 1 rotation. -- CPL_WCS_PLATESOL_6: Fit for zero point, 2 scales, 1 rotation, 1 shear.
This fucntion allows the zeropoint to be defined by shifting either the physical or the celestial coordinates of the reference point: -- CPL_WCS_MV_CRVAL: Keeps the physical point fixed and shifts the celestial -- CPL_WCS_MV_CRPIX: Keeps the celestial point fixed and shifts the physical
The output propertylist contains WCS relevant information only.