pro create_struct, struct, strname, tagnames, tag_descript, DIMEN = dimen, $ CHATTER = chatter, NODELETE = nodelete ;+ ; NAME: ; CREATE_STRUCT ; PURPOSE: ; Create an IDL structure from a list of tag names and dimensions ; EXPLANATION: ; Dynamically create an IDL structure variable from list of tag names ; and data types of arbitrary dimensions. Useful when the type of ; structure needed is not known until run time. ; ; Unlike the intrinsic function CREATE_STRUCT(), this procedure does not ; require the user to know the number of tags before run time. (Note ; there is no name conflict since the intrinsic CREATE_STRUCT is a ; function, and this file contains a procedure.) ; CALLING SEQUENCE: ; CREATE_STRUCT, STRUCT, strname, tagnames, tag_descript, ; [ DIMEN = , /CHATTER, /NODELETE ] ; ; INPUTS: ; STRNAME - name to be associated with structure (string) ; Must be unique for each structure created. Set ; STRNAME = '' to create an anonymous structure ; ; TAGNAMES - tag names for structure elements ; (string or string array) ; ; TAG_DESCRIPT - String descriptor for the structure, containing the ; tag type and dimensions. For example, 'A(2),F(3),I', would ; be the descriptor for a structure with 3 tags, strarr(2), ; fltarr(3) and Integer scalar, respectively. ; Allowed types are 'A' for strings, 'B' or 'L' for unsigned byte ; integers, 'I' for integers, 'J' for longword integers, ; 'F' or 'E' for floating point, 'D' for double precision ; 'C' for complex, and 'M' for double complex ; Uninterpretable characters in a format field are ignored. ; ; For vectors, the tag description can also be specified by ; a repeat count. For example, '16E,2J' would specify a ; structure with two tags, fltarr(16), and lonarr(2) ; ; OPTIONAL KEYWORD INPUTS: ; DIMEN - number of dimensions of structure array (default is 1) ; ; CHATTER - If /CHATTER is set, then CREATE_STRUCT will display ; the dimensions of the structure to be created, and prompt ; the user whether to continue. Default is no prompt. ; ; NODELETE - If /NODELETE is set, then the temporary file created ; CREATE_STRUCT will not be deleted upon exiting. See below ; ; OUTPUTS: ; STRUCT - IDL structure, created according to specifications ; ; EXAMPLES: ; ; IDL> create_struct, new, 'name',['tag1','tag2','tag3'], 'D(2),F,A(1)' ; ; will create a structure variable new, with structure name NAME ; ; To see the structure of new: ; ; IDL> help,new,/struc ; ** Structure NAME, 3 tags, 20 length: ; TAG1 DOUBLE Array(2) ; TAG2 FLOAT 0.0 ; TAG3 STRING Array(1) ; ; PROCEDURE: ; Generates a temporary procedure file using input information with ; the desired structure data types and dimensions hard-coded. ; This file is then executed with CALL_PROCEDURE. ; ; NOTES: ; If CREATE_STRUCT cannot write a temporary .pro file in the current ; directory, then it will write the temporary file in the getenv('HOME') ; directory. ; ; At present, can fail if a tag_name cannot be used as a proper ; structure component definition, e.g., '0.10' will not ; work, but a typical string like 'RA' or 'DEC' will. ; A partial workaround checks for characters '\' and '/' ; and '.' and converts them to '_'. in a tag_name. ; ; Note that 'L' now specifies a LOGICAL (byte) data type and not a ; a LONG data type for consistency with FITS binary tables ; ; RESTRICTIONS: ; The name of the structure must be unique, for each structure created. ; Otherwise, the new variable will have the same structure as the ; previous definition (because the temporary procedure will not be ; recompiled). ** No error message will be generated *** ; ; SUBROUTINES CALLED: ; FDECOMP, REPCHR() ; ; MODIFICATION HISTORY: ; Version 1.0 RAS January 1992 ; Modified 26 Feb 1992 for Rosat IDL Library (GAR) ; Modified Jun 1992 to accept arrays for tag elements -- KLV, Hughes STX ; Accept anonymous structures W. Landsman HSTX Sep. 92 ; Accept 'E' and 'J' format specifications W. Landsman Jan 93 ; 'L' format now stands for logical and not long array ; Accept repeat format for vectors W. Landsman Feb 93 ; Accept complex and double complex (for V4.0) W. Landsman Jul 95 ; Work for long structure definitions W. Landsman Aug 97 ; Converted to IDL V5.0 W. Landsman September 1997 ; Write temporary file in HOME directory if necessary W. Landsman Jul 98 ; Use OPENR,/DELETE for OS-independent file removal W. Landsman Jan 99 ; Use STRSPLIT() instead of GETTOK() W. Landsman July 2002 ; Assume since V5.3 W. Landsman Feb 2004 ;- ;------------------------------------------------------------------------------- if N_params() LT 4 then begin print,'Syntax - CREATE_STRUCT, STRUCT, strname, tagnames, tag_descript,' print,' [ DIMEN = , /CHATTER, /NODELETE ]' return endif if not keyword_set( chatter) then chatter = 0 ;default is 0 if (N_elements(dimen) eq 0) then dimen = 1 ;default is 1 if (dimen lt 1) then begin print,' Number of dimensions must be >= 1. Returning.' return endif ; For anonymous structure, strname = '' anonymous = 0b if (strlen( strtrim(strname,2)) EQ 0 ) then anonymous = 1b good_fmts = [ 'A', 'B', 'I', 'L', 'F', 'E', 'D', 'J','C','M' ] fmts = ["' '",'0B','0','0B','0.0','0.0','0.0D0','0L','complex(0)', $ 'dcomplex(0)'] arrs = [ 'strarr', 'bytarr', 'intarr', 'bytarr', 'fltarr', 'fltarr', $ 'dblarr', 'lonarr','complexarr','dcomplexarr'] ngoodf = N_elements( good_fmts ) ; If tagname is a scalar string separated by commas, convert to a string array if size(tagnames,/N_dimensions) EQ 0 then begin tagname = strsplit(tagnames,',',/EXTRACT) endif else tagname = tagnames Ntags = N_elements(tagname) ; Replace any illegal characters in the tag names with an underscore bad_chars = [ '\', '/', '.'] for k = 0, N_elements( bad_chars) -1 do $ tagname = repchr( tagname, bad_chars[k], '_' ) ; If user supplied a scalar string descriptor then we want to break it up ; into individual items. This is somewhat complicated because the string ; delimiter is not always a comma, e.g. if 'F,F(2,2),I(2)', so we need ; to check positions of parenthesis also. sz = size(tag_descript) if sz[0] EQ 0 then begin tagvar = strarr( Ntags) temptag = tag_descript for i = 0, Ntags - 1 do begin comma = strpos( temptag, ',' ) lparen = strpos( temptag, '(' ) rparen = strpos( temptag, ')' ) if ( comma GT lparen ) and (comma LT Rparen) then pos = Rparen+1 $ else pos = comma if pos EQ -1 then begin if i NE Ntags-1 then message, $ 'WARNING - could only parse ' + strtrim(i+1,2) + ' string descriptors' tagvar[i] = temptag goto, DONE endif else begin tagvar[i] = strmid( temptag, 0, pos ) temptag = strmid( temptag, pos+1, 1000) endelse endfor DONE: endif else tagvar = tag_descript ; create string array for IDL statements, to be written into ; 'temp_'+strname+'.pro' pro_string = strarr (ntags + 2) if (dimen EQ 1) then begin pro_string[0] = "struct = { " + strname + " $" pro_string[ntags+1] = " } " endif else begin dimen = long(dimen) ;Changed to LONG from FIX Mar 95 pro_string[0] = "struct " + " = replicate ( { " + strname + " $" pro_string[ntags+1] = " } , " + string(dimen) + ")" endelse for i = 0, ntags-1 do begin goodpos = -1 try = strupcase( tagvar[i] ) for j = 0,ngoodf-1 do begin fmt_pos = strpos( try, good_fmts[j] ) if ( fmt_pos GE 0 ) then begin goodpos = j goto, FOUND_FORMAT endif endfor print,' Format not recognized: ' + tagvar[i] print,' Allowed formats are :',good_fmts stop,' Redefine tag format (' + string(i) + ' ) or quit now' FOUND_FORMAT: if fmt_pos GT 0 then begin repeat_count = strmid( tagvar[i], 0, fmt_pos ) if strnumber( repeat_count, value ) then begin fmt = arrs[ goodpos ] + '(' + strtrim(fix(value), 2) + ')' endif else begin print,' Format not recognized: ' + tagvar[i] stop,' Redefine tag format (' + string(i) + ' ) or quit now' endelse endif else begin ; Break up the tag descriptor into a format and a dimension tagfmts = strmid( tagvar[i], 0, 1) tagdim = strtrim( strmid( tagvar[i], 1, 80),2) if strmid(tagdim,0,1) NE '(' then tagdim = '' if (tagdim EQ '') then fmt = fmts[goodpos] else $ fmt = arrs[goodpos] + tagdim endelse if anonymous and ( i EQ 0 ) then comma = '' else comma = " , " pro_string[i+1] = comma + tagname[i] + ": " + fmt + " $" endfor ; Check that this structure definition is OK (if chatter set to 1) if keyword_set ( Chatter ) then begin ans = '' print,' Structure ',strname,' will be defined according to the following:' temp = repchr( pro_string, '$', '') print, temp read,' OK to continue? (Y or N) ',ans if strmid(strupcase(ans),0,1) eq 'N' then begin print,' Returning at user request.' return endif endif ; --- Determine if a file already exists with same name as temporary file tempfile = 'temp_' + strlowcase( strname ) cdhome = 0 TEST_EXIST: if !VERSION.OS NE "vms" then begin ;Don't overwrite file in Unix EXIST: list = findfile( tempfile + '.pro', COUNT = Nfile) if (Nfile GT 0) then begin tempfile = tempfile + 'x' goto, EXIST endif endif ; ---- open temp file and create procedure ; ---- If problems writing into the current directory, try the HOME directory openw, unit, tempfile +'.pro', /get_lun, ERROR = err if (err LT 0) and (not cdhome) then begin cdhome = 1 tempfile = concat_dir(getenv('HOME'),tempfile) goto, TEST_EXIST endif fdecomp,tempfile,disk,dir,name printf, unit, 'pro ' + name + ', struct' for j = 0,N_elements(pro_string)-1 do $ printf, unit, strtrim( pro_string[j] ) printf, unit, 'return' printf, unit, 'end' free_lun, unit ; If using the HOME directory, it needs to be included in the IDL !PATH if cdhome then cd,getenv('HOME'),curr=curr Call_procedure, name, struct if cdhome then cd,curr if keyword_set( NODELETE ) then begin message,'Created temporary file ' + tempfile + '.pro',/INF return endif ; Delete the file in an OS-independent way openr, unit, tempfile + '.pro',/delete close,unit return end ;pro create_struct