#include "wcserr.h"

Data Structures
struct	prjprm
	Projection parameters. More...

Macros
#define	PVN 30
	Total number of projection parameters. More...

#define	PRJX2S_ARGS
	For use in declaring deprojection function prototypes. More...

#define	PRJS2X_ARGS
	For use in declaring projection function prototypes. More...

#define	PRJLEN (sizeof(struct prjprm)/sizeof(int))
	Size of the prjprm struct in int units. More...

#define	prjini_errmsg prj_errmsg
	Deprecated. More...

#define	prjprt_errmsg prj_errmsg
	Deprecated. More...

#define	prjset_errmsg prj_errmsg
	Deprecated. More...

#define	prjx2s_errmsg prj_errmsg
	Deprecated. More...

#define	prjs2x_errmsg prj_errmsg
	Deprecated. More...

Enumerations
enum	prj_errmsg_enum { PRJERR_SUCCESS = 0, PRJERR_NULL_POINTER = 1, PRJERR_BAD_PARAM = 2, PRJERR_BAD_PIX = 3, PRJERR_BAD_WORLD = 4 }

Functions
int	prjini (struct prjprm *prj)
	Default constructor for the prjprm struct. More...

int	prjfree (struct prjprm *prj)
	Destructor for the prjprm struct. More...

int	prjprt (const struct prjprm *prj)
	Print routine for the prjprm struct. More...

int	prjset (struct prjprm *prj)
	Generic setup routine for the prjprm struct. More...

int	prjx2s (PRJX2S_ARGS)
	Generic Cartesian-to-spherical deprojection. More...

int	prjs2x (PRJS2X_ARGS)
	Generic spherical-to-Cartesian projection. More...

int	azpset (struct prjprm *prj)
	Set up a prjprm struct for the zenithal/azimuthal perspective (`AZP`) projection. More...

int	azpx2s (PRJX2S_ARGS)
	Cartesian-to-spherical transformation for the zenithal/azimuthal perspective (`AZP`) projection. More...

int	azps2x (PRJS2X_ARGS)
	Spherical-to-Cartesian transformation for the zenithal/azimuthal perspective (`AZP`) projection. More...

int	szpset (struct prjprm *prj)
	Set up a prjprm struct for the slant zenithal perspective (`SZP`) projection. More...

int	szpx2s (PRJX2S_ARGS)
	Cartesian-to-spherical transformation for the slant zenithal perspective (`SZP`) projection. More...

int	szps2x (PRJS2X_ARGS)
	Spherical-to-Cartesian transformation for the slant zenithal perspective (`SZP`) projection. More...

int	tanset (struct prjprm *prj)
	Set up a prjprm struct for the gnomonic (`TAN`) projection. More...

int	tanx2s (PRJX2S_ARGS)
	Cartesian-to-spherical transformation for the gnomonic (`TAN`) projection. More...

int	tans2x (PRJS2X_ARGS)
	Spherical-to-Cartesian transformation for the gnomonic (`TAN`) projection. More...

int	stgset (struct prjprm *prj)
	Set up a prjprm struct for the stereographic (`STG`) projection. More...

int	stgx2s (PRJX2S_ARGS)
	Cartesian-to-spherical transformation for the stereographic (`STG`) projection. More...

int	stgs2x (PRJS2X_ARGS)
	Spherical-to-Cartesian transformation for the stereographic (`STG`) projection. More...

int	sinset (struct prjprm *prj)
	Set up a prjprm struct for the orthographic/synthesis (`SIN`) projection. More...

int	sinx2s (PRJX2S_ARGS)
	Cartesian-to-spherical transformation for the orthographic/synthesis (`SIN`) projection. More...

int	sins2x (PRJS2X_ARGS)
	Spherical-to-Cartesian transformation for the orthographic/synthesis (`SIN`) projection. More...

int	arcset (struct prjprm *prj)
	Set up a prjprm struct for the zenithal/azimuthal equidistant (`ARC`) projection. More...

int	arcx2s (PRJX2S_ARGS)
	Cartesian-to-spherical transformation for the zenithal/azimuthal equidistant (`ARC`) projection. More...

int	arcs2x (PRJS2X_ARGS)
	Spherical-to-Cartesian transformation for the zenithal/azimuthal equidistant (`ARC`) projection. More...

int	zpnset (struct prjprm *prj)
	Set up a prjprm struct for the zenithal/azimuthal polynomial (`ZPN`) projection. More...

int	zpnx2s (PRJX2S_ARGS)
	Cartesian-to-spherical transformation for the zenithal/azimuthal polynomial (`ZPN`) projection. More...

int	zpns2x (PRJS2X_ARGS)
	Spherical-to-Cartesian transformation for the zenithal/azimuthal polynomial (`ZPN`) projection. More...

int	zeaset (struct prjprm *prj)
	Set up a prjprm struct for the zenithal/azimuthal equal area (`ZEA`) projection. More...

int	zeax2s (PRJX2S_ARGS)
	Cartesian-to-spherical transformation for the zenithal/azimuthal equal area (`ZEA`) projection. More...

int	zeas2x (PRJS2X_ARGS)
	Spherical-to-Cartesian transformation for the zenithal/azimuthal equal area (`ZEA`) projection. More...

int	airset (struct prjprm *prj)
	Set up a prjprm struct for Airy's (`AIR`) projection. More...

int	airx2s (PRJX2S_ARGS)
	Cartesian-to-spherical transformation for Airy's (`AIR`) projection. More...

int	airs2x (PRJS2X_ARGS)
	Spherical-to-Cartesian transformation for Airy's (`AIR`) projection. More...

int	cypset (struct prjprm *prj)
	Set up a prjprm struct for the cylindrical perspective (`CYP`) projection. More...

int	cypx2s (PRJX2S_ARGS)
	Cartesian-to-spherical transformation for the cylindrical perspective (`CYP`) projection. More...

int	cyps2x (PRJS2X_ARGS)
	Spherical-to-Cartesian transformation for the cylindrical perspective (`CYP`) projection. More...

int	ceaset (struct prjprm *prj)
	Set up a prjprm struct for the cylindrical equal area (`CEA`) projection. More...

int	ceax2s (PRJX2S_ARGS)
	Cartesian-to-spherical transformation for the cylindrical equal area (`CEA`) projection. More...

int	ceas2x (PRJS2X_ARGS)
	Spherical-to-Cartesian transformation for the cylindrical equal area (`CEA`) projection. More...

int	carset (struct prjprm *prj)
	Set up a prjprm struct for the plate carrée (`CAR`) projection. More...

int	carx2s (PRJX2S_ARGS)
	Cartesian-to-spherical transformation for the plate carrée (`CAR`) projection. More...

int	cars2x (PRJS2X_ARGS)
	Spherical-to-Cartesian transformation for the plate carrée (`CAR`) projection. More...

int	merset (struct prjprm *prj)
	Set up a prjprm struct for Mercator's (`MER`) projection. More...

int	merx2s (PRJX2S_ARGS)
	Cartesian-to-spherical transformation for Mercator's (`MER`) projection. More...

int	mers2x (PRJS2X_ARGS)
	Spherical-to-Cartesian transformation for Mercator's (`MER`) projection. More...

int	sflset (struct prjprm *prj)
	Set up a prjprm struct for the Sanson-Flamsteed (`SFL`) projection. More...

int	sflx2s (PRJX2S_ARGS)
	Cartesian-to-spherical transformation for the Sanson-Flamsteed (`SFL`) projection. More...

int	sfls2x (PRJS2X_ARGS)
	Spherical-to-Cartesian transformation for the Sanson-Flamsteed (`SFL`) projection. More...

int	parset (struct prjprm *prj)
	Set up a prjprm struct for the parabolic (`PAR`) projection. More...

int	parx2s (PRJX2S_ARGS)
	Cartesian-to-spherical transformation for the parabolic (`PAR`) projection. More...

int	pars2x (PRJS2X_ARGS)
	Spherical-to-Cartesian transformation for the parabolic (`PAR`) projection. More...

int	molset (struct prjprm *prj)
	Set up a prjprm struct for Mollweide's (`MOL`) projection. More...

int	molx2s (PRJX2S_ARGS)
	Cartesian-to-spherical transformation for Mollweide's (`MOL`) projection. More...

int	mols2x (PRJS2X_ARGS)
	Spherical-to-Cartesian transformation for Mollweide's (`MOL`) projection. More...

int	aitset (struct prjprm *prj)
	Set up a prjprm struct for the Hammer-Aitoff (`AIT`) projection. More...

int	aitx2s (PRJX2S_ARGS)
	Cartesian-to-spherical transformation for the Hammer-Aitoff (`AIT`) projection. More...

int	aits2x (PRJS2X_ARGS)
	Spherical-to-Cartesian transformation for the Hammer-Aitoff (`AIT`) projection. More...

int	copset (struct prjprm *prj)
	Set up a prjprm struct for the conic perspective (`COP`) projection. More...

int	copx2s (PRJX2S_ARGS)
	Cartesian-to-spherical transformation for the conic perspective (`COP`) projection. More...

int	cops2x (PRJS2X_ARGS)
	Spherical-to-Cartesian transformation for the conic perspective (`COP`) projection. More...

int	coeset (struct prjprm *prj)
	Set up a prjprm struct for the conic equal area (`COE`) projection. More...

int	coex2s (PRJX2S_ARGS)
	Cartesian-to-spherical transformation for the conic equal area (`COE`) projection. More...

int	coes2x (PRJS2X_ARGS)
	Spherical-to-Cartesian transformation for the conic equal area (`COE`) projection. More...

int	codset (struct prjprm *prj)
	Set up a prjprm struct for the conic equidistant (`COD`) projection. More...

int	codx2s (PRJX2S_ARGS)
	Cartesian-to-spherical transformation for the conic equidistant (`COD`) projection. More...

int	cods2x (PRJS2X_ARGS)
	Spherical-to-Cartesian transformation for the conic equidistant (`COD`) projection. More...

int	cooset (struct prjprm *prj)
	Set up a prjprm struct for the conic orthomorphic (`COO`) projection. More...

int	coox2s (PRJX2S_ARGS)
	Cartesian-to-spherical transformation for the conic orthomorphic (`COO`) projection. More...

int	coos2x (PRJS2X_ARGS)
	Spherical-to-Cartesian transformation for the conic orthomorphic (`COO`) projection. More...

int	bonset (struct prjprm *prj)
	Set up a prjprm struct for Bonne's (`BON`) projection. More...

int	bonx2s (PRJX2S_ARGS)
	Cartesian-to-spherical transformation for Bonne's (`BON`) projection. More...

int	bons2x (PRJS2X_ARGS)
	Spherical-to-Cartesian transformation for Bonne's (`BON`) projection. More...

int	pcoset (struct prjprm *prj)
	Set up a prjprm struct for the polyconic (`PCO`) projection. More...

int	pcox2s (PRJX2S_ARGS)
	Cartesian-to-spherical transformation for the polyconic (`PCO`) projection. More...

int	pcos2x (PRJS2X_ARGS)
	Spherical-to-Cartesian transformation for the polyconic (`PCO`) projection. More...

int	tscset (struct prjprm *prj)
	Set up a prjprm struct for the tangential spherical cube (`TSC`) projection. More...

int	tscx2s (PRJX2S_ARGS)
	Cartesian-to-spherical transformation for the tangential spherical cube (`TSC`) projection. More...

int	tscs2x (PRJS2X_ARGS)
	Spherical-to-Cartesian transformation for the tangential spherical cube (`TSC`) projection. More...

int	cscset (struct prjprm *prj)
	Set up a prjprm struct for the COBE spherical cube (`CSC`) projection. More...

int	cscx2s (PRJX2S_ARGS)
	Cartesian-to-spherical transformation for the COBE spherical cube (`CSC`) projection. More...

int	cscs2x (PRJS2X_ARGS)
	Spherical-to-Cartesian transformation for the COBE spherical cube (`CSC`) projection. More...

int	qscset (struct prjprm *prj)
	Set up a prjprm struct for the quadrilateralized spherical cube (`QSC`) projection. More...

int	qscx2s (PRJX2S_ARGS)
	Cartesian-to-spherical transformation for the quadrilateralized spherical cube (`QSC`) projection. More...

int	qscs2x (PRJS2X_ARGS)
	Spherical-to-Cartesian transformation for the quadrilateralized spherical cube (`QSC`) projection. More...

int	hpxset (struct prjprm *prj)
	Set up a prjprm struct for the HEALPix (`HPX`) projection. More...

int	hpxx2s (PRJX2S_ARGS)
	Cartesian-to-spherical transformation for the HEALPix (`HPX`) projection. More...

int	hpxs2x (PRJS2X_ARGS)
	Spherical-to-Cartesian transformation for the HEALPix (`HPX`) projection. More...

int	xphset (struct prjprm *prj)

int	xphx2s (PRJX2S_ARGS)

int	xphs2x (PRJS2X_ARGS)

Variables
const char *	prj_errmsg []
	Status return messages. More...

const int	CONIC
	Identifier for conic projections. More...

const int	CONVENTIONAL
	Identifier for conventional projections. More...

const int	CYLINDRICAL
	Identifier for cylindrical projections. More...

const int	POLYCONIC
	Identifier for polyconic projections. More...

const int	PSEUDOCYLINDRICAL
	Identifier for pseudocylindrical projections. More...

const int	QUADCUBE
	Identifier for quadcube projections. More...

const int	ZENITHAL
	Identifier for zenithal/azimuthal projections. More...

const int	HEALPIX
	Identifier for the HEALPix projection. More...

const char	prj_categories [9][32]
	Projection categories. More...

const int	prj_ncode
	The number of recognized three-letter projection codes. More...

const char	prj_codes [28][4]
	Recognized three-letter projection codes. More...

Detailed Description

These routines implement the spherical map projections defined by the FITS WCS standard. They are based on the prjprm struct which contains all information needed for the computations. The struct contains some members 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 prjini() is provided to initialize the prjprm struct with default values, prjfree() reclaims any memory that may have been allocated to store an error message, and prjprt() prints its contents.

Setup routines for each projection with names of the form ???set(), where "???" is the down-cased three-letter projection code, compute intermediate values in the prjprm struct from parameters in it that were supplied by the user. The struct always needs to be set by the projection's setup routine but that need not be called explicitly - refer to the explanation of prjprm::flag.

Each map projection is implemented via separate functions for the spherical projection, ???s2x(), and deprojection, ???x2s().

A set of driver routines, prjset(), prjx2s(), and prjs2x(), provides a generic interface to the specific projection routines which they invoke via pointers-to-functions stored in the prjprm struct.

In summary, the routines are:

prjini() Initialization routine for the prjprm struct.
prjprt() Routine to print the prjprm struct.
prjset(), prjx2s(), prjs2x(): Generic driver routines
azpset(), azpx2s(), azps2x(): AZP (zenithal/azimuthal perspective)
szpset(), szpx2s(), szps2x(): SZP (slant zenithal perspective)
tanset(), tanx2s(), tans2x(): TAN (gnomonic)
stgset(), stgx2s(), stgs2x(): STG (stereographic)
sinset(), sinx2s(), sins2x(): SIN (orthographic/synthesis)
arcset(), arcx2s(), arcs2x(): ARC (zenithal/azimuthal equidistant)
zpnset(), zpnx2s(), zpns2x(): ZPN (zenithal/azimuthal polynomial)
zeaset(), zeax2s(), zeas2x(): ZEA (zenithal/azimuthal equal area)
airset(), airx2s(), airs2x(): AIR (Airy)
cypset(), cypx2s(), cyps2x(): CYP (cylindrical perspective)
ceaset(), ceax2s(), ceas2x(): CEA (cylindrical equal area)
carset(), carx2s(), cars2x(): CAR (Plate carée)
merset(), merx2s(), mers2x(): MER (Mercator)
sflset(), sflx2s(), sfls2x(): SFL (Sanson-Flamsteed)
parset(), parx2s(), pars2x(): PAR (parabolic)
molset(), molx2s(), mols2x(): MOL (Mollweide)
aitset(), aitx2s(), aits2x(): AIT (Hammer-Aitoff)
copset(), copx2s(), cops2x(): COP (conic perspective)
coeset(), coex2s(), coes2x(): COE (conic equal area)
codset(), codx2s(), cods2x(): COD (conic equidistant)
cooset(), coox2s(), coos2x(): COO (conic orthomorphic)
bonset(), bonx2s(), bons2x(): BON (Bonne)
pcoset(), pcox2s(), pcos2x(): PCO (polyconic)
tscset(), tscx2s(), tscs2x(): TSC (tangential spherical cube)
cscset(), cscx2s(), cscs2x(): CSC (COBE spherical cube)
qscset(), qscx2s(), qscs2x(): QSC (quadrilateralized spherical cube)
hpxset(), hpxx2s(), hpxs2x(): HPX (HEALPix)
xphset(), xphx2s(), xphs2x(): XPH (HEALPix polar, aka "butterfly")

Argument checking (projection routines):
The values of $\phi$ and $\theta$ (the native longitude and latitude) normally lie in the range $[-180^\circ,180^\circ]$ for $\phi$ , and $[-90^\circ,90^\circ]$ for $\theta$ . However, all projection routines will accept any value of $\phi$ and will not normalize it.

The projection routines do not explicitly check that $\theta$ lies within the range $[-90^\circ,90^\circ]$ . They do check for any value of $\theta$ that produces an invalid argument to the projection equations (e.g. leading to division by zero). The projection routines for AZP, SZP, TAN, SIN, ZPN, and COP also return error 2 if $(\phi,\theta)$ corresponds to the overlapped (far) side of the projection but also return the corresponding value of $(x,y)$ . This strict bounds checking may be relaxed at any time by setting prjprm::bounds%2 to 0 (rather than 1); the projections need not be reinitialized.

Argument checking (deprojection routines):
Error checking on the projected coordinates $(x,y)$ is limited to that required to ascertain whether a solution exists. Where a solution does exist no check is made that the value of $\phi$ and $\theta$ obtained lie within the ranges $[-180^\circ,180^\circ]$ for $\phi$ , and $[-90^\circ,90^\circ]$ for $\theta$ .

Accuracy:
No warranty is given for the accuracy of these routines (refer to the copyright notice); intending users must satisfy for themselves their adequacy for the intended purpose. However, closure to a precision of at least $0^\circ.0000000001$ of longitude and latitude has been verified for typical projection parameters on the $1^\circ$ degree graticule of native longitude and latitude (to within $5^\circ$ of any latitude where the projection may diverge). Refer to the tprj1.c and tprj2.c test routines that accompany this software.

Macro Definition Documentation

#define PVN 30

The total number of projection parameters numbered 0 to PVN-1.

#define PRJX2S_ARGS

Value:

struct prjprm *prj, int nx, int ny, int sxy, int spt, \

const double x[], const double y[], double phi[], double theta[], int stat[]

Preprocessor macro used for declaring deprojection function prototypes.

#define PRJS2X_ARGS

Value:

struct prjprm *prj, int nx, int ny, int sxy, int spt, \

const double phi[], const double theta[], double x[], double y[], int stat[]

Preprocessor macro used for declaring projection function prototypes.

#define PRJLEN (sizeof(struct prjprm)/sizeof(int))

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

#define prjini_errmsg prj_errmsg

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

#define prjprt_errmsg prj_errmsg

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

#define prjset_errmsg prj_errmsg

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

#define prjx2s_errmsg prj_errmsg

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

#define prjs2x_errmsg prj_errmsg

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

Enumeration Type Documentation

enum prj_errmsg_enum

Enumerator
PRJERR_SUCCESS
PRJERR_NULL_POINTER
PRJERR_BAD_PARAM
PRJERR_BAD_PIX
PRJERR_BAD_WORLD

Function Documentation

int prjini ( struct prjprm * prj)

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

Parameters

[out] prj Projection parameters.

Returns

Status return value:

0: Success.
1: Null prjprm pointer passed.

int prjfree ( struct prjprm * prj)

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

Parameters

[in] prj Projection parameters.

Returns

Status return value:

0: Success.
1: Null prjprm pointer passed.

int prjprt ( const struct prjprm * prj)

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

Parameters

[in] prj Projection parameters.

Returns

Status return value:

0: Success.
1: Null prjprm pointer passed.

int prjset ( struct prjprm * prj)

prjset() sets up a prjprm struct according to information supplied within it.

Note that this routine need not be called directly; it will be invoked by prjx2s() and prjs2x() if prj.flag is anything other than a predefined magic value.

The one important distinction between prjset() and the setup routines for the specific projections is that the projection code must be defined in the prjprm struct in order for prjset() to identify the required projection. Once prjset() has initialized the prjprm struct, prjx2s() and prjs2x() use the pointers to the specific projection and deprojection routines contained therein.

Parameters

[in,out] prj Projection parameters.

Returns

Status return value:

0: Success.
1: Null prjprm pointer passed.
2: Invalid projection parameters.

For returns > 1, a detailed error message is set in prjprm::err if enabled, see wcserr_enable().

int prjx2s ( PRJX2S_ARGS )

Deproject Cartesian $(x,y)$ coordinates in the plane of projection to native spherical coordinates $(\phi,\theta)$ .

The projection is that specified by prjprm::code.

Parameters

[in,out]	prj	Projection parameters.
[in]	nx,ny	Vector lengths.
[in]	sxy,spt	Vector strides.
[in]	x,y	Projected coordinates.
[out]	phi,theta	Longitude and latitude $(\phi,\theta)$ of the projected point in native spherical coordinates [deg].
[out]	stat	Status return value for each vector element: 0: Success. 1: Invalid value of .

Returns

Status return value:

0: Success.
1: Null prjprm pointer passed.
2: Invalid projection parameters.
3: One or more of the coordinates were invalid, as indicated by the stat vector.

For returns > 1, a detailed error message is set in prjprm::err if enabled, see wcserr_enable().

int prjs2x ( PRJS2X_ARGS )

Project native spherical coordinates $(\phi,\theta)$ to Cartesian $(x,y)$ coordinates in the plane of projection.

The projection is that specified by prjprm::code.

Parameters

[in,out]	prj	Projection parameters.
[in]	nphi,ntheta	Vector lengths.
[in]	spt,sxy	Vector strides.
[in]	phi,theta	Longitude and latitude $(\phi,\theta)$ of the projected point in native spherical coordinates [deg].
[out]	x,y	Projected coordinates.
[out]	stat	Status return value for each vector element: 0: Success. 1: Invalid value of $(\phi,\theta)$ .

Returns

Status return value:

0: Success.
1: Null prjprm pointer passed.
2: Invalid projection parameters.
4: One or more of the $(\phi,\theta)$ coordinates were, invalid, as indicated by the stat vector.

For returns > 1, a detailed error message is set in prjprm::err if enabled, see wcserr_enable().

int azpset ( struct prjprm * prj)

azpset() sets up a prjprm struct for a zenithal/azimuthal perspective (AZP) projection.

See prjset() for a description of the API.

int azpx2s ( PRJX2S_ARGS )

azpx2s() deprojects Cartesian $(x,y)$ coordinates in the plane of a zenithal/azimuthal perspective (AZP) projection to native spherical coordinates $(\phi,\theta)$ .

See prjx2s() for a description of the API.

int azps2x ( PRJS2X_ARGS )

azps2x() projects native spherical coordinates $(\phi,\theta)$ to Cartesian $(x,y)$ coordinates in the plane of a zenithal/azimuthal perspective (AZP) projection.

See prjs2x() for a description of the API.

int szpset ( struct prjprm * prj)

szpset() sets up a prjprm struct for a slant zenithal perspective (SZP) projection.

See prjset() for a description of the API.

int szpx2s ( PRJX2S_ARGS )

szpx2s() deprojects Cartesian $(x,y)$ coordinates in the plane of a slant zenithal perspective (SZP) projection to native spherical coordinates $(\phi,\theta)$ .

See prjx2s() for a description of the API.

int szps2x ( PRJS2X_ARGS )

szps2x() projects native spherical coordinates $(\phi,\theta)$ to Cartesian $(x,y)$ coordinates in the plane of a slant zenithal perspective (SZP) projection.

See prjs2x() for a description of the API.

int tanset ( struct prjprm * prj)

tanset() sets up a prjprm struct for a gnomonic (TAN) projection.

See prjset() for a description of the API.

int tanx2s ( PRJX2S_ARGS )

tanx2s() deprojects Cartesian $(x,y)$ coordinates in the plane of a gnomonic (TAN) projection to native spherical coordinates $(\phi,\theta)$ .

See prjx2s() for a description of the API.

int tans2x ( PRJS2X_ARGS )

tans2x() projects native spherical coordinates $(\phi,\theta)$ to Cartesian $(x,y)$ coordinates in the plane of a gnomonic (TAN) projection.

See prjs2x() for a description of the API.

int stgset ( struct prjprm * prj)

stgset() sets up a prjprm struct for a stereographic (STG) projection.

See prjset() for a description of the API.

int stgx2s ( PRJX2S_ARGS )

stgx2s() deprojects Cartesian $(x,y)$ coordinates in the plane of a stereographic (STG) projection to native spherical coordinates $(\phi,\theta)$ .

See prjx2s() for a description of the API.

int stgs2x ( PRJS2X_ARGS )

stgs2x() projects native spherical coordinates $(\phi,\theta)$ to Cartesian $(x,y)$ coordinates in the plane of a stereographic (STG) projection.

See prjs2x() for a description of the API.

int sinset ( struct prjprm * prj)

stgset() sets up a prjprm struct for an orthographic/synthesis (SIN) projection.

See prjset() for a description of the API.

int sinx2s ( PRJX2S_ARGS )

sinx2s() deprojects Cartesian $(x,y)$ coordinates in the plane of an orthographic/synthesis (SIN) projection to native spherical coordinates $(\phi,\theta)$ .

See prjx2s() for a description of the API.

int sins2x ( PRJS2X_ARGS )

sins2x() projects native spherical coordinates $(\phi,\theta)$ to Cartesian $(x,y)$ coordinates in the plane of an orthographic/synthesis (SIN) projection.

See prjs2x() for a description of the API.

int arcset ( struct prjprm * prj)

arcset() sets up a prjprm struct for a zenithal/azimuthal equidistant (ARC) projection.

See prjset() for a description of the API.

int arcx2s ( PRJX2S_ARGS )

arcx2s() deprojects Cartesian $(x,y)$ coordinates in the plane of a zenithal/azimuthal equidistant (ARC) projection to native spherical coordinates $(\phi,\theta)$ .

See prjx2s() for a description of the API.

int arcs2x ( PRJS2X_ARGS )

arcs2x() projects native spherical coordinates $(\phi,\theta)$ to Cartesian $(x,y)$ coordinates in the plane of a zenithal/azimuthal equidistant (ARC) projection.

See prjs2x() for a description of the API.

int zpnset ( struct prjprm * prj)

zpnset() sets up a prjprm struct for a zenithal/azimuthal polynomial (ZPN) projection.

See prjset() for a description of the API.

int zpnx2s ( PRJX2S_ARGS )

zpnx2s() deprojects Cartesian $(x,y)$ coordinates in the plane of a zenithal/azimuthal polynomial (ZPN) projection to native spherical coordinates $(\phi,\theta)$ .

See prjx2s() for a description of the API.

int zpns2x ( PRJS2X_ARGS )

zpns2x() projects native spherical coordinates $(\phi,\theta)$ to Cartesian $(x,y)$ coordinates in the plane of a zenithal/azimuthal polynomial (ZPN) projection.

See prjs2x() for a description of the API.

int zeaset ( struct prjprm * prj)

zeaset() sets up a prjprm struct for a zenithal/azimuthal equal area (ZEA) projection.

See prjset() for a description of the API.

int zeax2s ( PRJX2S_ARGS )

zeax2s() deprojects Cartesian $(x,y)$ coordinates in the plane of a zenithal/azimuthal equal area (ZEA) projection to native spherical coordinates $(\phi,\theta)$ .

See prjx2s() for a description of the API.

int zeas2x ( PRJS2X_ARGS )

zeas2x() projects native spherical coordinates $(\phi,\theta)$ to Cartesian $(x,y)$ coordinates in the plane of a zenithal/azimuthal equal area (ZEA) projection.

See prjs2x() for a description of the API.

int airset ( struct prjprm * prj)

airset() sets up a prjprm struct for an Airy (AIR) projection.

See prjset() for a description of the API.

int airx2s ( PRJX2S_ARGS )

airx2s() deprojects Cartesian $(x,y)$ coordinates in the plane of an Airy (AIR) projection to native spherical coordinates $(\phi,\theta)$ .

See prjx2s() for a description of the API.

int airs2x ( PRJS2X_ARGS )

airs2x() projects native spherical coordinates $(\phi,\theta)$ to Cartesian $(x,y)$ coordinates in the plane of an Airy (AIR) projection.

See prjs2x() for a description of the API.

int cypset ( struct prjprm * prj)

cypset() sets up a prjprm struct for a cylindrical perspective (CYP) projection.

See prjset() for a description of the API.

int cypx2s ( PRJX2S_ARGS )

cypx2s() deprojects Cartesian $(x,y)$ coordinates in the plane of a cylindrical perspective (CYP) projection to native spherical coordinates $(\phi,\theta)$ .

See prjx2s() for a description of the API.

int cyps2x ( PRJS2X_ARGS )

cyps2x() projects native spherical coordinates $(\phi,\theta)$ to Cartesian $(x,y)$ coordinates in the plane of a cylindrical perspective (CYP) projection.

See prjs2x() for a description of the API.

int ceaset ( struct prjprm * prj)

ceaset() sets up a prjprm struct for a cylindrical equal area (CEA) projection.

See prjset() for a description of the API.

int ceax2s ( PRJX2S_ARGS )

ceax2s() deprojects Cartesian $(x,y)$ coordinates in the plane of a cylindrical equal area (CEA) projection to native spherical coordinates $(\phi,\theta)$ .

See prjx2s() for a description of the API.

int ceas2x ( PRJS2X_ARGS )

ceas2x() projects native spherical coordinates $(\phi,\theta)$ to Cartesian $(x,y)$ coordinates in the plane of a cylindrical equal area (CEA) projection.

See prjs2x() for a description of the API.

int carset ( struct prjprm * prj)

carset() sets up a prjprm struct for a plate carrée (CAR) projection.

See prjset() for a description of the API.

int carx2s ( PRJX2S_ARGS )

carx2s() deprojects Cartesian $(x,y)$ coordinates in the plane of a plate carrée (CAR) projection to native spherical coordinates $(\phi,\theta)$ .

See prjx2s() for a description of the API.

int cars2x ( PRJS2X_ARGS )

cars2x() projects native spherical coordinates $(\phi,\theta)$ to Cartesian $(x,y)$ coordinates in the plane of a plate carrée (CAR) projection.

See prjs2x() for a description of the API.

int merset ( struct prjprm * prj)

merset() sets up a prjprm struct for a Mercator (MER) projection.

See prjset() for a description of the API.

int merx2s ( PRJX2S_ARGS )

merx2s() deprojects Cartesian $(x,y)$ coordinates in the plane of a Mercator (MER) projection to native spherical coordinates $(\phi,\theta)$ .

See prjx2s() for a description of the API.

int mers2x ( PRJS2X_ARGS )

mers2x() projects native spherical coordinates $(\phi,\theta)$ to Cartesian $(x,y)$ coordinates in the plane of a Mercator (MER) projection.

See prjs2x() for a description of the API.

int sflset ( struct prjprm * prj)

sflset() sets up a prjprm struct for a Sanson-Flamsteed (SFL) projection.

See prjset() for a description of the API.

int sflx2s ( PRJX2S_ARGS )

sflx2s() deprojects Cartesian $(x,y)$ coordinates in the plane of a Sanson-Flamsteed (SFL) projection to native spherical coordinates $(\phi,\theta)$ .

See prjx2s() for a description of the API.

int sfls2x ( PRJS2X_ARGS )

sfls2x() projects native spherical coordinates $(\phi,\theta)$ to Cartesian $(x,y)$ coordinates in the plane of a Sanson-Flamsteed (SFL) projection.

See prjs2x() for a description of the API.

int parset ( struct prjprm * prj)

parset() sets up a prjprm struct for a parabolic (PAR) projection.

See prjset() for a description of the API.

int parx2s ( PRJX2S_ARGS )

parx2s() deprojects Cartesian $(x,y)$ coordinates in the plane of a parabolic (PAR) projection to native spherical coordinates $(\phi,\theta)$ .

See prjx2s() for a description of the API.

int pars2x ( PRJS2X_ARGS )

pars2x() projects native spherical coordinates $(\phi,\theta)$ to Cartesian $(x,y)$ coordinates in the plane of a parabolic (PAR) projection.

See prjs2x() for a description of the API.

int molset ( struct prjprm * prj)

molset() sets up a prjprm struct for a Mollweide (MOL) projection.

See prjset() for a description of the API.

int molx2s ( PRJX2S_ARGS )

molx2s() deprojects Cartesian $(x,y)$ coordinates in the plane of a Mollweide (MOL) projection to native spherical coordinates $(\phi,\theta)$ .

See prjx2s() for a description of the API.

int mols2x ( PRJS2X_ARGS )

mols2x() projects native spherical coordinates $(\phi,\theta)$ to Cartesian $(x,y)$ coordinates in the plane of a Mollweide (MOL) projection.

See prjs2x() for a description of the API.

int aitset ( struct prjprm * prj)

aitset() sets up a prjprm struct for a Hammer-Aitoff (AIT) projection.

See prjset() for a description of the API.

int aitx2s ( PRJX2S_ARGS )

aitx2s() deprojects Cartesian $(x,y)$ coordinates in the plane of a Hammer-Aitoff (AIT) projection to native spherical coordinates $(\phi,\theta)$ .

See prjx2s() for a description of the API.

int aits2x ( PRJS2X_ARGS )

aits2x() projects native spherical coordinates $(\phi,\theta)$ to Cartesian $(x,y)$ coordinates in the plane of a Hammer-Aitoff (AIT) projection.

See prjs2x() for a description of the API.

int copset ( struct prjprm * prj)

copset() sets up a prjprm struct for a conic perspective (COP) projection.

See prjset() for a description of the API.

int copx2s ( PRJX2S_ARGS )

copx2s() deprojects Cartesian $(x,y)$ coordinates in the plane of a conic perspective (COP) projection to native spherical coordinates $(\phi,\theta)$ .

See prjx2s() for a description of the API.

int cops2x ( PRJS2X_ARGS )

cops2x() projects native spherical coordinates $(\phi,\theta)$ to Cartesian $(x,y)$ coordinates in the plane of a conic perspective (COP) projection.

See prjs2x() for a description of the API.

int coeset ( struct prjprm * prj)

coeset() sets up a prjprm struct for a conic equal area (COE) projection.

See prjset() for a description of the API.

int coex2s ( PRJX2S_ARGS )

coex2s() deprojects Cartesian $(x,y)$ coordinates in the plane of a conic equal area (COE) projection to native spherical coordinates $(\phi,\theta)$ .

See prjx2s() for a description of the API.

int coes2x ( PRJS2X_ARGS )

coes2x() projects native spherical coordinates $(\phi,\theta)$ to Cartesian $(x,y)$ coordinates in the plane of a conic equal area (COE) projection.

See prjs2x() for a description of the API.

int codset ( struct prjprm * prj)

codset() sets up a prjprm struct for a conic equidistant (COD) projection.

See prjset() for a description of the API.

int codx2s ( PRJX2S_ARGS )

codx2s() deprojects Cartesian $(x,y)$ coordinates in the plane of a conic equidistant (COD) projection to native spherical coordinates $(\phi,\theta)$ .

See prjx2s() for a description of the API.

int cods2x ( PRJS2X_ARGS )

cods2x() projects native spherical coordinates $(\phi,\theta)$ to Cartesian $(x,y)$ coordinates in the plane of a conic equidistant (COD) projection.

See prjs2x() for a description of the API.

int cooset ( struct prjprm * prj)

cooset() sets up a prjprm struct for a conic orthomorphic (COO) projection.

See prjset() for a description of the API.

int coox2s ( PRJX2S_ARGS )

coox2s() deprojects Cartesian $(x,y)$ coordinates in the plane of a conic orthomorphic (COO) projection to native spherical coordinates $(\phi,\theta)$ .

See prjx2s() for a description of the API.

int coos2x ( PRJS2X_ARGS )

coos2x() projects native spherical coordinates $(\phi,\theta)$ to Cartesian $(x,y)$ coordinates in the plane of a conic orthomorphic (COO) projection.

See prjs2x() for a description of the API.

int bonset ( struct prjprm * prj)

bonset() sets up a prjprm struct for a Bonne (BON) projection.

See prjset() for a description of the API.

int bonx2s ( PRJX2S_ARGS )

bonx2s() deprojects Cartesian $(x,y)$ coordinates in the plane of a Bonne (BON) projection to native spherical coordinates $(\phi,\theta)$ .

See prjx2s() for a description of the API.

int bons2x ( PRJS2X_ARGS )

bons2x() projects native spherical coordinates $(\phi,\theta)$ to Cartesian $(x,y)$ coordinates in the plane of a Bonne (BON) projection.

See prjs2x() for a description of the API.

int pcoset ( struct prjprm * prj)

pcoset() sets up a prjprm struct for a polyconic (PCO) projection.

See prjset() for a description of the API.

int pcox2s ( PRJX2S_ARGS )

pcox2s() deprojects Cartesian $(x,y)$ coordinates in the plane of a polyconic (PCO) projection to native spherical coordinates $(\phi,\theta)$ .

See prjx2s() for a description of the API.

int pcos2x ( PRJS2X_ARGS )

pcos2x() projects native spherical coordinates $(\phi,\theta)$ to Cartesian $(x,y)$ coordinates in the plane of a polyconic (PCO) projection.

See prjs2x() for a description of the API.

int tscset ( struct prjprm * prj)

tscset() sets up a prjprm struct for a tangential spherical cube (TSC) projection.

See prjset() for a description of the API.

int tscx2s ( PRJX2S_ARGS )

tscx2s() deprojects Cartesian $(x,y)$ coordinates in the plane of a tangential spherical cube (TSC) projection to native spherical coordinates $(\phi,\theta)$ .

See prjx2s() for a description of the API.

int tscs2x ( PRJS2X_ARGS )

tscs2x() projects native spherical coordinates $(\phi,\theta)$ to Cartesian $(x,y)$ coordinates in the plane of a tangential spherical cube (TSC) projection.

See prjs2x() for a description of the API.

int cscset ( struct prjprm * prj)

cscset() sets up a prjprm struct for a COBE spherical cube (CSC) projection.

See prjset() for a description of the API.

int cscx2s ( PRJX2S_ARGS )

cscx2s() deprojects Cartesian $(x,y)$ coordinates in the plane of a COBE spherical cube (CSC) projection to native spherical coordinates $(\phi,\theta)$ .

See prjx2s() for a description of the API.

int cscs2x ( PRJS2X_ARGS )

cscs2x() projects native spherical coordinates $(\phi,\theta)$ to Cartesian $(x,y)$ coordinates in the plane of a COBE spherical cube (CSC) projection.

See prjs2x() for a description of the API.

int qscset ( struct prjprm * prj)

qscset() sets up a prjprm struct for a quadrilateralized spherical cube (QSC) projection.

See prjset() for a description of the API.

int qscx2s ( PRJX2S_ARGS )

qscx2s() deprojects Cartesian $(x,y)$ coordinates in the plane of a quadrilateralized spherical cube (QSC) projection to native spherical coordinates $(\phi,\theta)$ .

See prjx2s() for a description of the API.

int qscs2x ( PRJS2X_ARGS )

qscs2x() projects native spherical coordinates $(\phi,\theta)$ to Cartesian $(x,y)$ coordinates in the plane of a quadrilateralized spherical cube (QSC) projection.

See prjs2x() for a description of the API.

int hpxset ( struct prjprm * prj)

hpxset() sets up a prjprm struct for a HEALPix (HPX) projection.

See prjset() for a description of the API.

int hpxx2s ( PRJX2S_ARGS )

hpxx2s() deprojects Cartesian $(x,y)$ coordinates in the plane of a HEALPix (HPX) projection to native spherical coordinates $(\phi,\theta)$ .

See prjx2s() for a description of the API.

int hpxs2x ( PRJS2X_ARGS )

hpxs2x() projects native spherical coordinates $(\phi,\theta)$ to Cartesian $(x,y)$ coordinates in the plane of a HEALPix (HPX) projection.

See prjs2x() for a description of the API.

int xphset ( struct prjprm * prj)

int xphx2s ( PRJX2S_ARGS )

int xphs2x ( PRJS2X_ARGS )

Variable Documentation

const char * prj_errmsg[]

Error messages to match the status value returned from each function.

const int CONIC

Identifier for conic projections, see prjprm::category.

const int CONVENTIONAL

Identifier for conventional projections, see prjprm::category.

const int CYLINDRICAL

Identifier for cylindrical projections, see prjprm::category.

const int POLYCONIC

Identifier for polyconic projections, see prjprm::category.

const int PSEUDOCYLINDRICAL

Identifier for pseudocylindrical projections, see prjprm::category.

const int QUADCUBE

Identifier for quadcube projections, see prjprm::category.

const int ZENITHAL

Identifier for zenithal/azimuthal projections, see prjprm::category.

const int HEALPIX

Identifier for the HEALPix projection, see prjprm::category.

const char prj_categories[9][32]

Names of the projection categories, all in lower-case except for "HEALPix".

Provided for information only, not used by the projection routines.

const int prj_ncode

The number of recognized three-letter projection codes (currently 27), see prj_codes.

const char prj_codes[27][4]

List of all recognized three-letter projection codes (currently 27), e.g. SIN, TAN, etc.

Data Structures

Macros

Enumerations

Functions

Variables

Detailed Description

Macro Definition Documentation

Enumeration Type Documentation

Function Documentation

Variable Documentation