#include <spc.h>
| Data Fields | |
| int | flag | 
| char | type [8] | 
| char | code [4] | 
| double | crval | 
| double | restfrq | 
| double | restwav | 
| double | pv [7] | 
| double | w [6] | 
| int | isGrism | 
| int | padding1 | 
| struct wcserr * | err | 
| void * | padding2 | 
| int(* | spxX2P )(SPX_ARGS) | 
| int(* | spxP2S )(SPX_ARGS) | 
| int(* | spxS2P )(SPX_ARGS) | 
| int(* | spxP2X )(SPX_ARGS) | 
| int spcprm::flag | 
| char spcprm::type | 
(Given) Four-letter spectral variable type, e.g "ZOPT" for CTYPEia = 'ZOPT-F2W'. (Declared as char[8] for alignment reasons.) 
| char spcprm::code | 
(Given) Three-letter spectral algorithm code, e.g "F2W" for CTYPEia = 'ZOPT-F2W'. 
| double spcprm::crval | 
(Given) Reference value (CRVALia), SI units. 
| double spcprm::restfrq | 
(Given) The rest frequency [Hz], and ...
| double spcprm::restwav | 
(Given) ... the rest wavelength in vacuo [m], only one of which need be given, the other should be set to zero. Neither are required if the  and
 and  spectral variables are both wave-characteristic, or both velocity-characteristic, types.
 spectral variables are both wave-characteristic, or both velocity-characteristic, types. 
| double spcprm::pv | 
(Given) Grism parameters for 'GRI' and 'GRA' algorithm codes: 
 , grating ruling density.
, grating ruling density.  , interference order.
, interference order.  , angle of incidence [deg].
, angle of incidence [deg].  , refractive index at the reference wavelength,
, refractive index at the reference wavelength,  .
.  ,
,  at the reference wavelength,
 at the reference wavelength,  (/m).
 (/m).  , grating tilt angle [deg].
, grating tilt angle [deg].  , detector tilt angle [deg].
, detector tilt angle [deg]. The remaining members of the spcprm struct are maintained by spcset() and must not be modified elsewhere:
| double spcprm::w | 
(Returned) Intermediate values:
 -type spectral variable at the reference point (SI units).
-type spectral variable at the reference point (SI units).  at the reference point (SI units).
 at the reference point (SI units). | int spcprm::isGrism | 
(Returned) Grism coordinates?
| int spcprm::padding1 | 
(An unused variable inserted for alignment purposes only.)
| struct wcserr * spcprm::err  [read] | 
(Returned) If enabled, when an error status is returned this structure contains detailed information about the error, see wcserr_enable().
void *padding2 (An unused variable inserted for alignment purposes only.)
| void* spcprm::padding2 | 
(Returned) The first and ...
(Returned) ... the second of the pointers to the transformation functions in the two-step algorithm chain  in the pixel-to-spectral direction where the non-linear transformation is from
 in the pixel-to-spectral direction where the non-linear transformation is from  to
 to  . The argument list, SPX_ARGS, is defined in spx.h.
. The argument list, SPX_ARGS, is defined in spx.h. 
(Returned) The first and ...
(Returned) ... the second of the pointers to the transformation functions in the two-step algorithm chain  in the spectral-to-pixel direction where the non-linear transformation is from
 in the spectral-to-pixel direction where the non-linear transformation is from  to
 to  . The argument list, SPX_ARGS, is defined in spx.h.
. The argument list, SPX_ARGS, is defined in spx.h. 
 1.5.6
 1.5.6