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/*============================================================================
WCSLIB 7.4 - an implementation of the FITS WCS standard.
Copyright (C) 1995-2021, Mark Calabretta
This file is part of WCSLIB.
WCSLIB is free software: you can redistribute it and/or modify it under the
terms of the GNU Lesser General Public License as published by the Free
Software Foundation, either version 3 of the License, or (at your option)
any later version.
WCSLIB is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for
more details.
You should have received a copy of the GNU Lesser General Public License
along with WCSLIB. If not, see http://www.gnu.org/licenses.
Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
http://www.atnf.csiro.au/people/Mark.Calabretta
$Id: twcssub.c,v 7.4 2021/01/31 02:24:52 mcalabre Exp $
*=============================================================================
*
* twcssub tests wcssub() which extracts the coordinate description for a
* subimage from a wcsprm struct.
*
*---------------------------------------------------------------------------*/
#include <stdio.h>
#include <string.h>
#include <wcs.h>
#include <wcserr.h>
// In real life these would be encoded as FITS header keyrecords.
const int NAXIS = 4;
const double CRPIX[4] = { 1025.0, 64.0, 512.0, 513.0};
const double PC[4][4] = {{ 1.1, 0.0, 0.0, 0.0},
{ 0.0, 1.0, 0.0, 0.0},
{ 0.0, 0.0, 1.0, 0.1},
{ 0.0, 0.0, 0.2, 1.0}};
const double CDELT[4] = {-9.2e-6, 10.0, 1.0, -1.0};
char CUNIT[4][16] = {"m", "s", "deg", "deg"};
char CTYPE[4][16] = {"WAVE-F2W", "TIME", "XLAT-SZP", "XLON-SZP"};
const double CRVAL[4] = {0.214982042, -2e3, -30.0, 150.0};
const double LONPOLE = 150.0;
const double LATPOLE = 999.0;
const double RESTFRQ = 1.42040575e9;
const double RESTWAV = 0.0;
char CNAME[4][16] = {"Wavelength", "Time", "Latitude", "Longitude"};
int NPS, NPV;
struct pvcard PV[10];
struct pscard PS[10];
int main()
{
int axes[4], i, j, nsub, status;
struct wcsprm wcs, wcsext;
double *pcij;
PV[0].i = 1; // Frequency on axis 1.
PV[0].m = 1; // Parameter number 1.
PV[0].value = -1.0; // PV1_1.
PV[1].i = 3; // Latitude on axis 3.
PV[1].m = 1; // Parameter number 1.
PV[1].value = 2.0; // PV3_1.
PV[2].i = 3; // Latitude on axis 3.
PV[2].m = 2; // Parameter number 2.
PV[2].value = 210.0; // PV3_2.
PV[3].i = 3; // Latitude on axis 3.
PV[3].m = 3; // Parameter number 3.
PV[3].value = 60.0; // PV3_3.
NPV = 4;
PS[0].i = 2; // Time on axis 2.
PS[0].m = 1; // Parameter number 1.
strcpy(PS[0].value, "UTC"); // PS2_1.
NPS = 1;
wcs.flag = -1;
wcsini(1, NAXIS, &wcs);
for (j = 0; j < NAXIS; j++) {
wcs.crpix[j] = CRPIX[j];
}
pcij = wcs.pc;
for (i = 0; i < NAXIS; i++) {
for (j = 0; j < NAXIS; j++) {
*(pcij++) = PC[i][j];
}
}
for (i = 0; i < NAXIS; i++) {
wcs.cdelt[i] = CDELT[i];
}
for (i = 0; i < NAXIS; i++) {
strcpy(wcs.cunit[i], &CUNIT[i][0]);
strcpy(wcs.ctype[i], &CTYPE[i][0]);
strcpy(wcs.cname[i], &CNAME[i][0]);
}
for (i = 0; i < NAXIS; i++) {
wcs.crval[i] = CRVAL[i];
}
wcs.lonpole = LONPOLE;
wcs.latpole = LATPOLE;
wcs.restfrq = RESTFRQ;
wcs.restwav = RESTWAV;
wcs.npv = NPV;
for (i = 0; i < NPV; i++) {
wcs.pv[i] = PV[i];
}
wcs.nps = NPS;
for (i = 0; i < NPS; i++) {
wcs.ps[i] = PS[i];
}
// Initialize the wcsprm struct.
wcserr_enable(1);
(void) wcsset(&wcs);
printf("Testing WCSLIB subimage extraction routine (twcssub.c)\n"
"------------------------------------------------------\n");
printf("\nInitial contents of wcsprm struct:\n");
wcsprt(&wcs);
// Extract the coordinate description for a subimage and add a new axis.
nsub = 4;
wcsext.flag = -1;
axes[0] = WCSSUB_LONGITUDE;
axes[1] = WCSSUB_LATITUDE;
axes[2] = -(WCSSUB_SPECTRAL | WCSSUB_STOKES);
axes[3] = 0;
printf("\n\nExtracted contents of wcsprm struct:\n");
if (wcssub(1, &wcs, &nsub, axes, &wcsext)) {
wcsperr(&wcsext, "");
} else if (nsub == 0) {
printf("None of the requested subimage axes were found.\n");
} else if (wcsset(&wcsext)) {
wcsperr(&wcsext, "");
} else {
wcsprt(&wcsext);
}
// Set it up for failure by setting PC1_3 non-zero.
*(wcs.pc+2) = 1.0;
nsub = 2;
axes[0] = 4;
axes[1] = 3;
status = wcssub(1, &wcs, &nsub, axes, &wcsext);
if (status == WCSERR_NON_SEPARABLE) {
printf("\n\nReceived wcssub status %d as expected for a non-separable "
"subimage\ncoordinate system.\n", WCSERR_NON_SEPARABLE);
} else {
printf("\n\nERROR: expected wcssub status %d for a non-separable "
"subimage coordinate\nsystem, but received status %d instead.\n",
WCSERR_NON_SEPARABLE, status);
}
wcsfree(&wcs);
wcsfree(&wcsext);
return 0;
}
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