/usr/share/gnudatalanguage/astrolib/fxpar.pro is in gdl-astrolib 2018.02.16+dfsg-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 | FUNCTION FXPAR, HDR, NAME, ABORT, COUNT=MATCHES, COMMENT=COMMENTS, $
START=START, PRECHECK=PRECHECK, POSTCHECK=POSTCHECK, $
NOCONTINUE = NOCONTINUE, DATATYPE=DATATYPE, $
NULL=K_NULL, NAN=NAN, MISSING=MISSING
;+
; NAME:
; FXPAR()
; PURPOSE:
; Obtain the value of a parameter in a FITS header.
; EXPLANATION:
; The first 8 chacters of each element of HDR are searched for a match to
; NAME. If the keyword is one of those allowed to take multiple values
; ("HISTORY", "COMMENT", or " " (blank)), then the value is taken
; as the next 72 characters. Otherwise, it is assumed that the next
; character is "=", and the value (and optional comment) is then parsed
; from the last 71 characters. An error occurs if there is no parameter
; with the given name.
;
; If the value is too long for one line, it may be continued on to the
; the next input card, using the CONTINUE Long String Keyword convention.
; For more info, http://fits.gsfc.nasa.gov/registry/continue_keyword.html
;
;
; Complex numbers are recognized as two numbers separated by one or more
; space characters.
;
; If a numeric value has no decimal point (or E or D) it is returned as
; type LONG. If it contains more than 8 numerals, or contains the
; character 'D', then it is returned as type DOUBLE. Otherwise it is
; returned as type FLOAT. If an integer is too large to be stored as
; type LONG, then it is returned as DOUBLE.
;
; If a keyword is in the header and has no value, then the default
; missing value is returned as explained below. This can be
; distinguished from the case where the keyword is not found by the fact
; that COUNT=0 in that case, while existing keywords without a value will
; be returned with COUNT=1 or more.
;
; CALLING SEQUENCE:
; Result = FXPAR( HDR, NAME [, ABORT, COUNT=, COMMENT=, /NOCONTINUE ] )
;
; Result = FXPAR(HEADER,'DATE') ;Finds the value of DATE
; Result = FXPAR(HEADER,'NAXIS*') ;Returns array dimensions as
; ;vector
; REQUIRED INPUTS:
; HDR = FITS header string array (e.g. as returned by FXREAD). Each
; element should have a length of 80 characters
; NAME = String name of the parameter to return. If NAME is of the
; form 'keyword*' then an array is returned containing values
; of keywordN where N is an integer. The value of keywordN
; will be placed in RESULT(N-1). The data type of RESULT will
; be the type of the first valid match of keywordN
; found, unless DATATYPE is given.
; OPTIONAL INPUT:
; ABORT = String specifying that FXPAR should do a RETALL if a
; parameter is not found. ABORT should contain a string to be
; printed if the keyword parameter is not found. If not
; supplied, FXPAR will return with a negative !err if a keyword
; is not found.
; OUTPUT:
; The returned value of the function is the value(s) associated with the
; requested keyword in the header array.
;
; If the parameter is complex, double precision, floating point, long or
; string, then the result is of that type. Apostrophes are stripped from
; strings. If the parameter is logical, 1 is returned for T, and 0 is
; returned for F.
;
; If NAME was of form 'keyword*' then a vector of values are returned.
;
; OPTIONAL INPUT KEYWORDS:
; DATATYPE = A scalar value, indicating the type of vector
; data. All keywords will be cast to this type.
; Default: based on first keyword.
; Example: DATATYPE=0.0D (cast data to double precision)
; START = A best-guess starting position of the sought-after
; keyword in the header. If specified, then FXPAR
; first searches for scalar keywords in the header in
; the index range bounded by START-PRECHECK and
; START+POSTCHECK. This can speed up keyword searches
; in large headers. If the keyword is not found, then
; FXPAR searches the entire header.
;
; If not specified then the entire header is searched.
; Searches of the form 'keyword*' also search the
; entire header and ignore START.
;
; Upon return START is changed to be the position of
; the newly found keyword. Thus the best way to
; search for a series of keywords is to search for
; them in the order they appear in the header like
; this:
;
; START = 0L
; P1 = FXPAR('P1', START=START)
; P2 = FXPAR('P2', START=START)
;
; PRECHECK = If START is specified, then PRECHECK is the number
; of keywords preceding START to be searched.
; Default: 5
; POSTCHECK = If START is specified, then POSTCHECK is the number
; of keywords after START to be searched.
; Default: 20
; /NOCONTINUE = If set, then continuation lines will not be read, even
; if present in the header
; MISSING = By default, this routine returns 0 when keyword values are
; not found. This can be overridden by using the MISSING
; keyword, e.g. MISSING=-1.
; /NAN = If set, then return Not-a-Number (!values.f_nan) for missing
; values. Ignored if keyword MISSING is present.
; /NULL = If set, then return !NULL (undefined) for missing values.
; Ignored if MISSING or /NAN is present, or if earlier than IDL
; version 8.0. If multiple values would be returned, then
; MISSING= or /NAN should be used instead of /NULL, making sure
; that the datatype is consistent with the non-missing values,
; e.g. MISSING='' for strings, MISSING=-1 for integers, or
; MISSING=-1.0 or /NAN for floating point. /NAN should not be
; used if the datatype would otherwise be integer.
; OPTIONAL OUTPUT KEYWORD:
; COUNT = Optional keyword to return a value equal to the number of
; parameters found by FXPAR.
; COMMENTS= Array of comments associated with the returned values.
;
; PROCEDURE CALLS:
; GETTOK(), VALID_NUM
; SIDE EFFECTS:
;
; The system variable !err is set to -1 if parameter not found, 0 for a
; scalar value returned. If a vector is returned it is set to the number
; of keyword matches found. This use of !ERR is deprecated.
;
; If a keyword occurs more than once in a header, a warning is given,
; and the first occurence is used. However, if the keyword is "HISTORY",
; "COMMENT", or " " (blank), then multiple values are returned.
;
; NOTES:
; The functions SXPAR() and FXPAR() are nearly identical, although
; FXPAR() has slightly more sophisticated parsing. There is no
; particular reason for having two nearly identical procedures, but
; both are too widely used to drop either one.
;
; REVISION HISTORY:
; Version 1, William Thompson, GSFC, 12 April 1993.
; Adapted from SXPAR
; Version 2, William Thompson, GSFC, 14 October 1994
; Modified to use VALID_NUM instead of STRNUMBER. Inserted
; additional call to VALID_NUM to trap cases where character
; strings did not contain quotation marks.
; Version 3, William Thompson, GSFC, 22 December 1994
; Fixed bug with blank keywords, following suggestion by Wayne
; Landsman.
; Version 4, Mons Morrison, LMSAL, 9-Jan-98
; Made non-trailing ' for string tag just be a warning (not
; a fatal error). It was needed because "sxaddpar" had an
; error which did not write tags properly for long strings
; (over 68 characters)
; Version 5, Wayne Landsman GSFC, 29 May 1998
; Fixed potential problem with overflow of LONG values
; Version 6, Craig Markwardt, GSFC, 28 Jan 1998,
; Added CONTINUE parsing
; Version 7, Craig Markwardt, GSFC, 18 Nov 1999,
; Added START, PRE/POSTCHECK keywords for better
; performance
; Version 8, Craig Markwardt, GSFC, 08 Oct 2003,
; Added DATATYPE keyword to cast vector keywords type
; Version 9, Paul Hick, 22 Oct 2003, Corrected bug (NHEADER-1)
; Version 10, W. Landsman, GSFC 2 May 2012
; Keywords of form "name_0" could confuse vector extractions
; Version 11 W. Landsman, GSFC 24 Apr 2014
; Don't convert LONG64 numbers to to double precision
; Version 12, William Thompson, 13-Aug-2014
; Add keywords MISSING, /NAN, and /NULL
; Version 13, W. Landsman 25-Jan-2018
; Return ULONG64 integer if LONG64 would overflow
;-
;------------------------------------------------------------------------------
;
; Check the number of parameters.
;
IF N_PARAMS() LT 2 THEN BEGIN
PRINT,'Syntax: result = FXPAR( HDR, NAME [, ABORT ])'
RETURN, -1
ENDIF
;
; Determine the default value for missing data.
;
CASE 1 OF
N_ELEMENTS(MISSING) EQ 1: MISSING_VALUE = MISSING
KEYWORD_SET(NAN): MISSING_VALUE = !VALUES.F_NAN
KEYWORD_SET(K_NULL) AND !VERSION.RELEASE GE '8.': $
DUMMY = EXECUTE('MISSING_VALUE = !NULL')
ELSE: MISSING_VALUE = 0
ENDCASE
VALUE = MISSING_VALUE
;
; Determine the abort condition.
;
IF N_PARAMS() LE 2 THEN BEGIN
ABORT_RETURN = 0
ABORT = 'FITS Header'
END ELSE ABORT_RETURN = 1
IF ABORT_RETURN THEN ON_ERROR,1 ELSE ON_ERROR,2
;
; Check for valid header. Check header for proper attributes.
;
S = SIZE(HDR)
IF ( S[0] NE 1 ) OR ( S[2] NE 7 ) THEN $
MESSAGE,'FITS Header (first parameter) must be a string array'
;
; Convert the selected keyword NAME to uppercase.
;
NAM = STRTRIM( STRUPCASE(NAME) )
;
; Determine if NAME is of form 'keyword*'. If so, then strip off the '*', and
; set the VECTOR flag. One must consider the possibility that NAM is an empty
; string.
;
NAMELENGTH1 = (STRLEN(NAM) - 1) > 1
IF STRPOS( NAM, '*' ) EQ NAMELENGTH1 THEN BEGIN
NAM = STRMID( NAM, 0, NAMELENGTH1)
VECTOR = 1 ;Flag for vector output
NAME_LENGTH = STRLEN(NAM) ;Length of name
NUM_LENGTH = 8 - NAME_LENGTH ;Max length of number portion
IF NUM_LENGTH LE 0 THEN MESSAGE, $
'Keyword length must be 8 characters or less'
;
; Otherwise, extend NAME with blanks to eight characters.
;
ENDIF ELSE BEGIN
WHILE STRLEN(NAM) LT 8 DO NAM = NAM + ' '
VECTOR = 0
ENDELSE
;
; If of the form 'keyword*', then find all instances of 'keyword' followed by
; a number. Store the positions of the located keywords in NFOUND, and the
; value of the number field in NUMBER.
;
IF N_ELEMENTS(START) EQ 0 THEN START = -1L
START = LONG(START[0])
IF NOT VECTOR AND START GE 0 THEN BEGIN
IF N_ELEMENTS(PRECHECK) EQ 0 THEN PRECHECK = 5
IF N_ELEMENTS(POSTCHECK) EQ 0 THEN POSTCHECK = 20
NHEADER = N_ELEMENTS(HDR)
MN = (START - PRECHECK) > 0
MX = (START + POSTCHECK) < (NHEADER-1) ;Corrected bug
KEYWORD = STRMID(HDR[MN:MX], 0, 8)
ENDIF ELSE BEGIN
RESTART:
START = -1L
KEYWORD = STRMID( HDR, 0, 8)
ENDELSE
IF VECTOR THEN BEGIN
NFOUND = WHERE(STRPOS(KEYWORD,NAM) GE 0, MATCHES)
IF ( MATCHES GT 0 ) THEN BEGIN
NUMST= STRMID(HDR[NFOUND], NAME_LENGTH, NUM_LENGTH)
NUMBER = INTARR(MATCHES)-1
FOR I = 0, MATCHES-1 DO $
IF VALID_NUM( NUMST[I], NUM) THEN NUMBER[I] = NUM
IGOOD = WHERE(NUMBER GE 0, MATCHES)
IF MATCHES GT 0 THEN BEGIN
NFOUND = NFOUND[IGOOD]
NUMBER = NUMBER[IGOOD]
G = WHERE(NUMBER GT 0, MATCHES)
IF MATCHES GT 0 THEN NUMBER = NUMBER[G]
ENDIF
ENDIF
;
; Otherwise, find all the instances of the requested keyword. If more than
; one is found, and NAME is not one of the special cases, then print an error
; message.
;
ENDIF ELSE BEGIN
NFOUND = WHERE(KEYWORD EQ NAM, MATCHES)
IF MATCHES EQ 0 AND START GE 0 THEN GOTO, RESTART
IF START GE 0 THEN NFOUND = NFOUND + MN
IF (MATCHES GT 1) AND (NAM NE 'HISTORY ') AND $
(NAM NE 'COMMENT ') AND (NAM NE '') THEN $
MESSAGE,/INFORMATIONAL, 'WARNING- Keyword ' + $
NAM + 'located more than once in ' + ABORT
IF (MATCHES GT 0) THEN START = NFOUND[MATCHES-1]
ENDELSE
;
; Extract the parameter field from the specified header lines. If one of the
; special cases, then done.
;
IF MATCHES GT 0 THEN BEGIN
VALUE = MISSING_VALUE
LINE = HDR[NFOUND]
SVALUE = STRTRIM( STRMID(LINE,9,71),2)
IF (NAM EQ 'HISTORY ') OR (NAM EQ 'COMMENT ') OR $
(NAM EQ ' ') THEN BEGIN
VALUE = STRTRIM( STRMID(LINE,8,72),2)
COMMENTS = STRARR(N_ELEMENTS(VALUE))
;
; Otherwise, test to see if the parameter contains a string, signalled by
; beginning with a single quote character (') (apostrophe).
;
END ELSE FOR I = 0,MATCHES-1 DO BEGIN
IF ( STRMID(SVALUE[I],0,1) EQ "'" ) THEN BEGIN
TEST = STRMID( SVALUE[I],1,STRLEN( SVALUE[I] )-1)
NEXT_CHAR = 0
OFF = 0
VALUE = ''
;
; Find the next apostrophe.
;
NEXT_APOST:
ENDAP = STRPOS(TEST, "'", NEXT_CHAR)
IF ENDAP LT 0 THEN MESSAGE, $
'WARNING: Value of '+NAME+' invalid in '+ABORT+ " (no trailing ')", /info
VALUE = VALUE + STRMID( TEST, NEXT_CHAR, ENDAP-NEXT_CHAR )
;
; Test to see if the next character is also an apostrophe. If so, then the
; string isn't completed yet. Apostrophes in the text string are signalled as
; two apostrophes in a row.
;
IF STRMID( TEST, ENDAP+1, 1) EQ "'" THEN BEGIN
VALUE = VALUE + "'"
NEXT_CHAR = ENDAP+2
GOTO, NEXT_APOST
ENDIF
;
; Extract the comment, if any.
;
SLASH = STRPOS(TEST, "/", ENDAP)
IF SLASH LT 0 THEN COMMENT = '' ELSE $
COMMENT = STRMID(TEST, SLASH+1, STRLEN(TEST)-SLASH-1)
;
; CM 19 Sep 1997
; This is a string that could be continued on the next line. Check this
; possibility with the following four criteria: *1) Ends with '&'
; (2) Next line is CONTINUE (3) LONGSTRN keyword is present (recursive call to
; FXPAR) 4. /NOCONTINE is not set
IF NOT KEYWORD_SET(NOCONTINUE) THEN BEGIN
OFF = OFF + 1
VAL = STRTRIM(VALUE,2)
IF (STRLEN(VAL) GT 0) AND $
(STRMID(VAL, STRLEN(VAL)-1, 1) EQ '&') AND $
(STRMID(HDR[NFOUND[I]+OFF],0,8) EQ 'CONTINUE') THEN BEGIN
IF (SIZE(FXPAR(HDR, 'LONGSTRN',/NOCONTINUE)))[1] EQ 7 THEN BEGIN
VALUE = STRMID(VAL, 0, STRLEN(VAL)-1)
TEST = HDR[NFOUND[I]+OFF]
TEST = STRMID(TEST, 8, STRLEN(TEST)-8)
TEST = STRTRIM(TEST, 2)
IF STRMID(TEST, 0, 1) NE "'" THEN MESSAGE, $
'ERROR: Invalidly CONTINUEd string in '+ABORT
NEXT_CHAR = 1
GOTO, NEXT_APOST
ENDIF
ENDIF
ENDIF
;
; If not a string, then separate the parameter field from the comment field.
; If there is no value field, then use the default "missing" value.
;
ENDIF ELSE BEGIN
VALUE = MISSING_VALUE
TEST = SVALUE[I]
IF TEST EQ '' THEN BEGIN
COMMENT = ''
GOTO, GOT_VALUE
ENDIF
SLASH = STRPOS(TEST, "/")
IF SLASH GE 0 THEN BEGIN
COMMENT = STRMID(TEST, SLASH+1, STRLEN(TEST)-SLASH-1)
IF SLASH GT 0 THEN TEST = STRMID(TEST, 0, SLASH) ELSE $
GOTO, GOT_VALUE
END ELSE COMMENT = ''
;
; Find the first word in TEST. Is it a logical value ('T' or 'F')?
;
TEST2 = TEST
VALUE = GETTOK(TEST2,' ')
TEST2 = STRTRIM(TEST2,2)
IF ( VALUE EQ 'T' ) THEN BEGIN
VALUE = 1
END ELSE IF ( VALUE EQ 'F' ) THEN BEGIN
VALUE = 0
END ELSE BEGIN
;
; Test to see if a complex number. It's a complex number if the value and the
; next word, if any, both are valid numbers.
;
IF STRLEN(TEST2) EQ 0 THEN GOTO, NOT_COMPLEX
VALUE2 = GETTOK(TEST2,' ')
IF VALID_NUM(VALUE,VAL1) AND VALID_NUM(VALUE2,VAL2) $
THEN BEGIN
VALUE = COMPLEX(VAL1,VAL2)
GOTO, GOT_VALUE
ENDIF
;
; Not a complex number. Decide if it is a floating point, double precision,
; or integer number. If an error occurs, then a string value is returned.
; If the integer is not within the range of a valid long value, then it will
; be converted to a double.
;
NOT_COMPLEX:
ON_IOERROR, GOT_VALUE
VALUE = TEST
IF NOT VALID_NUM(VALUE) THEN GOTO, GOT_VALUE
IF (STRPOS(VALUE,'.') GE 0) OR (STRPOS(VALUE,'E') $
GE 0) OR (STRPOS(VALUE,'D') GE 0) THEN BEGIN
IF ( STRPOS(VALUE,'D') GT 0 ) OR $
( STRLEN(VALUE) GE 8 ) THEN BEGIN
VALUE = DOUBLE(VALUE)
END ELSE VALUE = FLOAT(VALUE)
ENDIF ELSE BEGIN
LMAX = 2.0D^31 - 1.0D
LMIN = -2.0D^31 ;Typo fixed Feb 2010
IF STRMID(VALUE,0,1) NE '-' THEN BEGIN
VALUE = ULONG64(VALUE)
IF VALUE LT ULONG64(2)^63-1 THEN VALUE = LONG64(VALUE)
ENDIF ELSE VALUE = LONG64(VALUE)
if (VALUE GE LMIN) and (VALUE LE LMAX) THEN $
VALUE = LONG(VALUE)
ENDELSE
;
GOT_VALUE:
ON_IOERROR, NULL
ENDELSE
ENDELSE ; if string
;
; Add to vector if required.
;
IF VECTOR THEN BEGIN
MAXNUM = MAX(NUMBER)
IF ( I EQ 0 ) THEN BEGIN
IF N_ELEMENTS(DATATYPE) EQ 0 THEN BEGIN
;; Data type determined from keyword
SZ_VALUE = SIZE(VALUE)
ENDIF ELSE BEGIN
;; Data type requested by user
SZ_VALUE = SIZE(DATATYPE[0])
ENDELSE
RESULT = MAKE_ARRAY( MAXNUM, TYPE=SZ_VALUE[1])
COMMENTS = STRARR(MAXNUM)
ENDIF
RESULT[ NUMBER[I]-1 ] = VALUE
COMMENTS[ NUMBER[I]-1 ] = COMMENT
ENDIF ELSE BEGIN
COMMENTS = COMMENT
ENDELSE
ENDFOR
;
; Set the value of !ERR for the number of matches for vectors, or simply 0
; otherwise.
;
IF VECTOR THEN BEGIN
!ERR = MATCHES
RETURN, RESULT
ENDIF ELSE !ERR = 0
;
; Error point for keyword not found.
;
ENDIF ELSE BEGIN
IF ABORT_RETURN THEN MESSAGE,'Keyword '+NAM+' not found in '+ABORT
!ERR = -1
ENDELSE
;
RETURN, VALUE
END
|