#ifndef lint
static char SccsId[] = "%W% %G%";
#endif
/* Module: readfith.c (Read FITS Header)
* Purpose: Parse FITS header for specific parameter fields
* Subroutine: read_fitsheader() returns: void
* Subroutine: no_fitscomment() returns: void
* Copyright: 1998 Smithsonian Astrophysical Observatory
* You may do anything you like with this file except remove
* this copyright. The Smithsonian Astrophysical Observatory
* makes no representations about the suitability of this
* software for any purpose. It is provided "as is" without
* express or implied warranty.
* Modified: {0} Michael VanHilst initial version 23 January 1989
* {1} Tim Cornwell (NRAO) not reject BITPIX < 0 1 Feb 1990
* {1} MVH BSDonly strings.h compatability 19 Feb 1990
* {2} Doug Mink (SAO) initialize WCS 7 Jul 1995
* {3} Doug Mink (SAO) print WCS info 16 Oct 1995
* {4} Doug Mink (SAO) set wcscoor and wcscom 17 Jul 1998
* {4} Doug Mink change WCS command initialization 14 Aug 1998
* {5} Doug Mink drop WCS command initialization 29 Sep 1998
* {n} <who> -- <does what> -- <when>
*/
#include <stdio.h> /* get stderr, NULL, etc. */
#ifndef VMS
#ifdef SYSV
#include <string.h> /* strlen, strcat, strcpy, strrchr */
#else
#include <strings.h> /* strlen, strcat, strcpy, rindex */
#endif
#else
#include <string.h> /* strlen, strcat, strcpy, strrchr */
#endif
#include <X11/Xlib.h> /* X window stuff */
#include <X11/Xutil.h> /* X window manager stuff */
#include "hfiles/define.h" /* define MIN, MAX, etc. */
#include "hfiles/struct.h" /* declare structure types */
#include "hfiles/extern.h" /* extern main parameter structure */
/*
* Subroutine: read_fitsheader
* Purpose: Find important FITS parameters in FITS header
* Returns: 1 if success, else 0
*/
static int get_keyint(), get_keyfloat();
int read_fitsheader ( header, length, bitpix, naxis, naxes, scale, bias )
char *header;
int length;
int *bitpix;
int *naxis;
int *naxes;
float *scale;
float *bias;
{
struct WorldCoor *wcsinit();
char *header0;
header0 = header;
/* first card is assumed to be SIMPLE = T, so skip it */
header += 80;
if( (*bitpix = get_keyint(header,"BITPIX ", 80, 1)) == 0 )
return(0);
if( (*bitpix % 8) != 0 ) {
(void)fprintf(stderr,
"BITPIX = %d: not 8, 16, 32, -16, -32, or -64\n", *bitpix);
return(0);
}
header += 80;
if( (*naxis = get_keyint(header, "NAXIS ", 80, 1)) <= 0 )
return(0);
header += 80;
if( (naxes[0] = get_keyint(header, "NAXIS1 ", 80, 1)) <= 0 )
return(0);
header += 80;
if( (naxes[1] = get_keyint(header, "NAXIS2 ", 80, 1)) <= 0 )
return(0);
header += 80;
length -= 400;
if( *naxis > 2 ) {
if( (naxes[2] = get_keyint(header, "NAXIS3 ", 80, 1)) <= 0 )
return(0);
header += 80;
length -= 80;
}
if( get_keyfloat(header, "BZERO ", length, bias, 0) == 0 )
*bias = 0.0;
if( get_keyfloat(header, "BSCALE ", length, scale, 0) == 0 )
*scale = 1.0;
wcs = wcsinit (header0);
(void)setwcslin (wcs, 1);
if (control.verbose) {
if (wcs)
wcscent (wcs);
else
wcserr ();
}
wcsoutinit (wcs, getwcscoor());
return(1);
}
/*
* Subroutine: get_keyint
* Purpose: Return the int value in the data field for a given FITS
* header keyword. If key not found, return 0.
*/
static int get_keyint ( header, keyword, length, report_error)
char *header; /* buffer start */
char *keyword; /* keyword to match */
int length; /* if zero, search up to "END" keyword */
int report_error; /* if > 0, fatal if key not found */
{
int key_not_end, val;
int i;
void no_fitscomment();
key_not_end = (strncmp(keyword, "END ", 8) != 0);
for( i=0; i<length; i+=80 ) {
/* check for END keyword marking end of header, unless END is the key */
if( key_not_end && strncmp(header+i,"END ",8) == 0 )
break;
/* check for desired keyword */
if( strncmp(header+i,keyword,8) == 0 ) {
no_fitscomment (header+i+10, 20);
if( (sscanf(header+i+10,"%d", &val) != 1) || (val == 0) ) {
(void)fprintf(stderr,
"Bad integer value for %s keyword in FITS header\n",
keyword);
return( 0 );
}
return( val );
}
}
if( report_error )
(void)fprintf(stderr, "No `%s' keyword in FITS header\n", keyword);
return( 0 );
}
/*
* Subroutine: get_keyfloat
* Purpose: Return the float value in the data field for a given FITS
* header keyword. If key not found, return 0.
*/
static void fix_exponent();
static int get_keyfloat ( header, keyword, length, val, report_error)
char *header; /* buffer start */
char *keyword; /* keyword to match */
int length; /* if zero, search up to "END" keyword */
float *val; /* float to recieve value if found */
int report_error; /* if > 0, fatal if key not found */
{
int key_not_end;
int i;
void no_fitscomment();
key_not_end = (strncmp(keyword, "END ", 8) != 0);
for( i=0; i<length; i+=80 ) {
/* check for END keyword marking end of header, unless END is the key */
if( key_not_end && strncmp(header+i,"END ",8) == 0 )
break;
/* check for desired keyword */
if( strncmp(header+i,keyword,8) == 0 ) {
no_fitscomment (header+i+10, 20);
fix_exponent (header+i+10, 20);
if( sscanf(header+i+10,"%f", val) != 1 ) {
(void)fprintf(stderr,
"Bad numerical value for %s keyword in FITS header\n",
keyword);
return( 0 );
}
return( 1 );
}
}
if( report_error )
(void)fprintf(stderr, "No `%s' keyword in FITS header\n", keyword);
return( 0 );
}
/*
* Subroutine: no_fitscomment
* Purpose: Terminate the data field at an comment indicator. The FITS
* standard allows comments immediately after any data.
*/
void no_fitscomment ( line, count )
char *line;
int count;
{
int i;
for( i=0; i<count; i++ )
if( line[i] == '/' ) line[i] = '\0';
}
/*
* Subroutine: fix_exponent
* Purpose: Change misguided exponents using D to use E. This problem
* reportedly appears in output from some IRAF tasks.
*/
static void fix_exponent ( line, count )
char *line;
int count;
{
int i;
for( i = 0; (i < count) && (line[i] != '\0'); i++ ) {
if( line[i] == 'D' ) line[i] = 'E';
if( line[i] == 'd' ) line[i] = 'e';
}
}
/* Jul 7 1998 Change setlinmode() to setwcslin()
* Jul 17 1998 Use getwcscom() and getwcscoor() instead of external variables
* Aug 14 1998 Use setwcscom() instead of wcscominit()
* Sep 29 1998 Drop setwcscom() as it is in wcsinit()
*/
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