Pro sxaddpar, Header, Name, Value, Comment, Location, before=before, $ after=after , format=format, pdu = pdu ;+ ; NAME: ; SXADDPAR ; PURPOSE: ; Add or modify a parameter in a FITS header array. ; ; CALLING SEQUENCE: ; SXADDPAR, Header, Name, Value, [ Comment, Location, ; BEFORE =, AFTER = , FORMAT= , /PDU] ; ; INPUTS: ; Header = String array containing FITS or STSDAS header. The ; length of each element must be 80 characters. If not ; defined, then SXADDPAR will create an empty FITS header array. ; ; Name = Name of parameter. If Name is already in the header the value ; and possibly comment fields are modified. Otherwise a new ; record is added to the header. If name is equal to 'COMMENT' ; or 'HISTORY' or a blank string then the value will be added to ; the record without replacement. For these cases, the comment ; parameter is ignored. ; ; Value = Value for parameter. The value expression must be of the ; correct type, e.g. integer, floating or string. String values ; of 'T' or 'F' are considered logical values. ; ; OPTIONAL INPUT PARAMETERS: ; Comment = String field. The '/' is added by this routine. Added ; starting in position 31. If not supplied, or set equal to ; '', then the previous comment field is retained (when found) ; ; Location = Keyword string name. The parameter will be placed before the ; location of this keyword. This parameter is identical to ; the BEFORE keyword and is kept only for consistency with ; earlier versions of SXADDPAR. ; ; OPTIONAL INPUT KEYWORD PARAMETERS: ; BEFORE = Keyword string name. The parameter will be placed before the ; location of this keyword. For example, if BEFORE='HISTORY' ; then the parameter will be placed before the first history ; location. This applies only when adding a new keyword; ; keywords already in the header are kept in the same position. ; ; AFTER = Same as BEFORE, but the parameter will be placed after the ; location of this keyword. This keyword takes precedence over ; BEFORE. ; ; FORMAT = Specifies FORTRAN-like format for parameter, e.g. "F7.3". A ; scalar string should be used. For complex numbers the format ; should be defined so that it can be applied separately to the ; real and imaginary parts. If not supplied then the default is ; 'G19.12' for double precision, and 'G14.7' for floating point. ; ; /PDU = specifies keyword is to be added to the primary data unit ; header. If it already exists, it's current value is updated in ; the current position and it is not moved. ; OUTPUTS: ; Header = updated FITS header array. ; ; EXAMPLE: ; Add a keyword 'TELESCOP' with the value 'KPNO-4m' and comment 'Name ; of Telescope' to an existing FITS header h. ; ; IDL> sxaddpar, h, 'TELESCOPE','KPNO-4m','Name of Telescope' ; NOTES: ; The functions SXADDPAR() and FXADDPAR() are nearly identical, with the ; major difference being that FXADDPAR forces required FITS keywords ; BITPIX, NAXISi, EXTEND, PCOUNT, GCOUNT to appear in the required order ; in the header. There is no particular reason for having two nearly ; identical procedures, but both are too widely used to drop either one. ; ; All HISTORY records are inserted in order at the end of the header. ; ; All COMMENT records are also inserted in order at the end of the header ; header, but before the HISTORY records. The BEFORE and AFTER keywords ; can override this. ; ; All records with no keyword (blank) are inserted in order at the end of ; the header, but before the COMMENT and HISTORY records. The BEFORE and ; AFTER keywords can override this. ; RESTRICTIONS: ; Warning -- Parameters and names are not checked ; against valid FITS parameter names, values and types. ; ; MODIFICATION HISTORY: ; DMS, RSI, July, 1983. ; D. Lindler Oct. 86 Added longer string value capability ; Converted to NEWIDL D. Lindler April 90 ; Added Format keyword, J. Isensee, July, 1990 ; Added keywords BEFORE and AFTER. K. Venkatakrishna, May '92 ; Pad string values to at least 8 characters W. Landsman April 94 ; Aug 95: added /PDU option and changed routine to update last occurence ; of an existing keyword (the one SXPAR reads) instead of the ; first occurence. ; Comment for string data can start after column 32 W. Landsman June 97 ; Make sure closing quote supplied with string value W. Landsman June 98 ; Converted to IDL V5.0 W. Landsman June 98 ; Increase precision of default formatting of double precision floating ; point values. C. Gehman, JPL September 1998 ; Mar 2000, D. Lindler, Modified to use capital E instead of lower case ; e for exponential formats. ; Apr 2000, Make user-supplied format upper-case W. Landsman ; Oct 2001, Treat COMMENT or blank string like HISTORY keyword W. Landsman ; Jan 2002, Allow BEFORE, AFTER to apply to COMMENT keywords W. Landsman ; ;- if N_params() LT 3 then begin ;Need at least 3 parameters print,'Syntax - Sxaddpar, Header, Name, Value, [Comment, Postion' print,' BEFORE = ,AFTER = , FORMAT = ]' return endif ; Define a blank line and the END line ENDLINE = 'END' +string(replicate(32b,77)) ;END line BLANK = string(replicate(32b,80)) ;BLANK line ; ; If Location parameter not defined, set it equal to 'END ' ; if ( N_params() GT 4 ) then loc = strupcase(location) else $ if keyword_set( BEFORE) then loc = strupcase(before) else $ if keyword_set( AFTER) then loc = strupcase(after) else $ if keyword_set( PDU) then loc = 'BEGIN EX' else $ loc = 'END' while strlen(loc) lt 8 do loc = loc + ' ' if N_params() lt 4 then comment = '' ;Is comment field specified? n = N_elements(header) ;# of lines in FITS header if (n EQ 0) then begin ;header defined? header=strarr(10) ;no, make it. header[0]=ENDLINE n=10 endif else begin s = size(header) ;check for string type if (s[0] ne 1) or (s[2] ne 7) then $ message,'FITS Header (first parameter) must be a string array' endelse ; Make sure Name is 8 characters long nn = string(replicate(32b,8)) ;8 char name strput,nn,strupcase(name) ;insert name ; Extract first 8 characters of each line of header, and locate END line keywrd = strmid(header,0,8) ;Header keywords iend = where(keywrd eq 'END ',nfound) if nfound eq 0 then header[0]=ENDLINE ;no end, insert at beginning iend = iend[0] > 0 ;Make scalar ; History, comment and "blank" records are treated differently from the ; others. They are simply added to the header array whether there are any ; already there or not. if (nn EQ 'HISTORY ') or (nn EQ 'COMMENT ') or $ (nn EQ ' ') then begin ;add history record? ; ; If the header array needs to grow, then expand it in increments of 5 lines. ; if iend GE (n-1) then begin header = [header,replicate(blank,5)] ;yes, add 5. n = N_elements(header) endif ; Format the record newline = blank strput,newline,nn+string(value),0 ; ; If a history record, then append to the record just before the end. ; if nn EQ 'HISTORY ' then begin header[iend] = newline ;add history rec. header[iend+1] = endline ; ; The comment record is placed immediately after the last previous comment ; record, or immediately before the first history record, unless overridden by ; either the BEFORE or AFTER keywords. ; endif else if nn EQ 'COMMENT ' then begin if loc EQ 'END ' then loc = 'COMMENT ' iloc = where(keywrd EQ loc, nloc) if nloc EQ 0 then iloc = where(keywrd EQ 'HISTORY ', nloc) if nloc gt 0 then begin i = iloc[nloc-1] if keyword_set(after) or (loc EQ 'COMMENT ') then i = i+1 < iend if i gt 0 then header=[header[0:i-1],newline,header[i:n-1]] $ else header=[newline,header[0:n-1]] endif else begin header[iend] = newline header[iend+1] = endline endelse ; ; The "blank" record is placed immediately after the last previous "blank" ; record, or immediately before the first comment or history record, unless ; overridden by either the BEFORE or AFTER keywords. ; ENDIF ELSE BEGIN if loc EQ 'END ' then loc = ' ' iloc = where(keywrd[0:iend] EQ loc, nloc) if nloc gt 0 then begin i = iloc[0] if keyword_set(after) and loc ne 'HISTORY ' then i = i+1 < iend if i gt 0 then header=[header[0:i-1],newline,header[i:n-1]] $ else header=[newline,header[0:n-1]] endif else begin iloc = where(keywrd EQ 'COMMENT ', nloc) if nloc Eq 0 then iloc = where(keywrd EQ 'HISTORY ', nloc) if nloc GT 0 then begin i = iloc[0] if i gt 0 then header=[header[0:i-1],newline,header[i:n-1]] $ else header=[newline,header[0:n-1]] endif else begin header[iend] = newline header[iend+1] = endline endelse endelse endelse RETURN endif ; Find location to insert keyword. Save the existing comment if user did ; not supply a new one. Comment starts after column 32 for numeric data, ; after the slash (but at least after column 20) for string data. ipos = where(keywrd eq nn,nfound) if nfound gt 0 then begin i = ipos[nfound-1] if comment eq '' then begin ;save comment? if strmid(header[i],10,1) NE "'" then $ comment=strmid(header[i],32,48) else begin slash = strpos(header[i],'/', 20) if slash NE -1 then $ comment = strmid(header[i], slash+1, 80) else $ comment = string(replicate(32B,80)) endelse endif goto, REPLACE endif if loc ne '' then begin iloc = where(keywrd eq loc,nloc) if nloc gt 0 then begin i = iloc[0] if keyword_set(after) and loc ne 'HISTORY ' then i = i+1 < iend if i gt 0 then header=[header[0:i-1],blank,header[i:n-1]] $ else header=[blank,header[0:n-1]] goto, REPLACE endif endif ; At this point keyword and location parameters were not found, so a new ; line is added at the end of the FITS header if iend lt (n-1) then begin ;Not found, add more? header[iend+1] = ENDLINE ;no, already long enough. i = iend ;position to add. endif else begin ;must lengthen. header = [header,replicate(blank,5)] ;add an element on the end header[n]=ENDLINE ;save "END" i =n-1 ;add to end end ; Now put value into keyword at line i REPLACE: h=blank ;80 blanks strput,h,nn+'= ' ;insert name and =. apost = "'" ;quote a quote type = size(value) ;get type of value parameter if type[0] ne 0 then $ message,'Keyword Value (third parameter) must be scalar' case type[1] of ;which type? 7: begin upval = strupcase(value) ;force upper case. if (upval eq 'T') or (upval eq 'F') then begin strput,h,upval,29 ;insert logical value. end else begin ;other string? if strlen(value) gt 18 then begin ;long string strput, h, apost + strmid(value,0,68) + apost + $ ' /' + comment,10 header[i] = h return endif strput, h, apost + value,10 ;insert string val strput, h, apost, 11 + (strlen(value)>8) ;pad string vals endelse ;to at least 8 chars endcase 5: BEGIN IF (N_ELEMENTS(format) EQ 1) THEN $ ; use format keyword v = string(value, FORMAT='('+strupcase(format)+')') $ ELSE v = STRING(value, FORMAT='(G19.12)') s = strlen(v) ; right justify strput, h, v, (30-s)>10 END else: begin if (N_elements(format) eq 1) then $ ;use format keyword v = string(value, FORMAT='('+strupcase(format)+')' ) else $ v = strtrim(strupcase(value),2) ;convert to string, default format s = strlen(v) ;right justify strput,h,v,(30-s)>10 ;insert end endcase strput,h,' /',30 ;add ' /' strput, h, comment, 32 ;add comment header[i] = h ;save line return end