pro my_create_struct, struct, strname, tagnames, tag_descript, DIMEN = dimen, $ CHATTER = chatter ;+ ; NAME: ; MY_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. ; CALLING SEQUENCE: ; MY_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. ; OUTPUTS: ; STRUCT - IDL structure, created according to specifications ; EXAMPLES: ; IDL> my_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: ; 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 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: ; GETTOK(), OS_FAMILY(), 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 ; Modified 27/12/98 JPhB to use resolve_routine. ; Modified 04/12/03 JPhB to use execute. No more temporary routine ; is used ;- ;------------------------------------------------------------------------------- npar = N_params() if (npar LT 4) then begin print,'Syntax - MY_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 ; --- Determine if a file already exists with same name as temporary ; file tempfile = 'temp_' + strlowcase( strname ) 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 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 tagname = tagnames sz_name = size( tagnames ) if ( sz_name(0) Eq 0 ) then begin tempname = tagnames tagname = gettok(tempname,',') while (tempname NE '') do tagname = [ tagname, gettok(tempname,',') ] 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(0) = "struct = { "+ " $" 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 Nel=(size(pro_string))(1) sstr='' FOR i=0L, Nel-1 DO BEGIN sstr=sstr+repchr( pro_string(i), '$', '') ENDFOR toto=execute(sstr) return end ;pro create_struct