Messages from Usenet group comp.lang.idl-pvwave, compiled by Paulo Penteado
Robert Chatfield wrote: > > Has anyone written a routine that puts reasonable labels on maps drawn > by > idl? I think this routine is pretty good (if not terribly verbose)... ; Procedure to label the lat/lon values around the boundary of a map. ; ; Originator: Andrew F. Loughe (2/22/95) pro map_label, color=color, charsize=charsize, $ lhs=lhs, rhs=rhs, $ latdel=latdel, londel=londel, $ nudgex=nudgex, nudgey=nudgey, help=help ; Print a help message to the IDLTERM. if (n_elements(help) gt 0) then begin message, ' map_label, color=color, charsize=charsize,' + $ ' lhs=lhs, rhs=rhs, latdel=latdel, londel=londel,' + $ ' nudgex=nudgex, nudgey=nudgey, help=help' endif ; Set some defaults if (n_elements(color) eq 0) then color = !p.color if (n_elements(charsize) eq 0) then charsize = 0.8 lhs = keyword_set (lhs) rhs = keyword_set (rhs) if (lhs eq 0 and rhs eq 0) then lhs = 1 if (n_elements(latdel) eq 0) then latdel = 30 if (n_elements(londel) eq 0) then londel = 30 if (n_elements(nudgex) eq 0) then nudgex=0 if (n_elements(nudgey) eq 0) then nudgey=0 on_error, 2 ; Get lat/lon boundaries of the map. lonmin = !map.out(2) lonmax = !map.out(3) latmin = !map.out(4) latmax = !map.out(5) if (lonmin eq lonmax) then lonmax = lonmin + 360. DX = abs (lonmax - lonmin) ;Compute number of plots/page numperpage= (!p.multi(1) * !p.multi(2)) > 1 ; Determine character height and width. Apply charsize. char_ht = convert_coord([0,!d.y_ch_size],/device,/to_norm) char_ht = char_ht(1) * 1.0 if (!d.name ne 'X' and charsize gt 1.) then $ char_ht = char_ht * charsize char_wd = convert_coord([0,!d.x_ch_size],/device,/to_norm) char_wd = char_wd(1) ; Nudging factor (convert from data to normalized) y_avg = .5*(latmin + latmax) nudgex1 = convert_coord( [nudgex,y_avg], /data, /to_norm ) nudgex2 = convert_coord( [nudgex+nudgex,y_avg], /data, /to_norm ) nudgex = nudgex2 - nudgex1 nudgex = nudgex(0) x_avg = .5*(lonmin + lonmax) nudgey1 = convert_coord( [x_avg,nudgey], /data, /to_norm ) nudgey2 = convert_coord( [x_avg,nudgey+nudgey], /data, /to_norm ) nudgey = nudgey2 - nudgey1 nudgey = nudgey(1) ; Test to see how close the lower longitude points are. ; If they are too close, then place longitude labels along EQ. xypos1 = convert_coord([lonmin, latmin], /data, /to_norm) xypos2 = convert_coord([lonmin+DX/2., latmin], /data, /to_norm) bottom = 'yes' if ( abs(xypos1(0) - xypos2(0)) lt .2/numperpage ) then bottom='no' ; Plot longitude labels along BOTTOM boundary of the map. for i = fix(lonmin), fix(lonmax) do begin if ( (i mod londel) eq 0 ) then begin ii = fix(abs(i)) if (i gt 180) then ii = abs(360 - ii) ; Determine text of longitude label. append = '' if (i gt 0 and i lt 180) then append='E' if (i lt 0 or i gt 180) then append='W' if (i gt 360 and i lt 540) then append='E' if (i gt 540 and i lt 720) then append='w' if ( (abs(i) mod 180) eq 0 ) then append='' if ( (abs(i) mod 360) eq 0 ) then ii='0' label = strcompress(string(ii), /rem) + append ; Determine where to place longitude label. xypos = convert_coord([i, latmin], /data, /to_norm) x = xypos(0) y = !y.window(0) - (char_ht)*1.2 + nudgey ; Some projections have longitude labels at EQ. if ( bottom eq 'no' ) then begin xypos = convert_coord([i, .5], /data, /to_norm) x = xypos(0) y = xypos(1) if ( x ge !x.window(0)+char_wd*2. and $ x le !x.window(1)-char_wd*2. and $ y ge !y.window(0)+char_ht and $ y le !y.window(1)-char_ht ) then $ xyouts,x,y,label,charsize=charsize,color=color,align=.5,/nor m endif else begin ; Plot longitude labels at bottom of the map. if ( x ge !x.window(0)-char_wd*2. and $ x le !x.window(1)+char_wd*2. ) then $ xyouts,x,y,label,charsize=charsize,color=color,align=.5,/nor m endelse endif endfor ; i ; Plot latitude labels along LEFT or RIGHT boundary of the map. for i = latmin, latmax do begin if ( (i mod latdel eq 0) ) then begin ii = fix(abs(i)) ; Determine text of latitude label. append='' if (i lt 0) then append='S' if (i gt 0) then append='N' if (i eq 0) then ii='EQ' label = strcompress(string(ii), /rem) + append ; Determine where to place latitude label. ; Work in from the far left to find the y position. if (lhs eq 1) then begin for x1 = lonmin-10., lonmax, .1 do begin xypos = convert_coord( [x1, i], /data, /to_norm) xypos2 = xypos xypos2(0) = xypos2(0) - char_wd xypos2(1) = xypos2(1) + char_ht if (xypos2(0) ge !x.window(0) and xypos2(1) ge $ !y.window(0) and xypos2(1) le !y.window(1)) $ then goto, jump2 endfor ; Work in from the far right to find the y position. endif else begin for x1 = lonmax+10., lonmin, -.1 do begin xypos = convert_coord( [x1, i], /data, /to_norm) xypos2 = xypos xypos2(0) = xypos2(0) + char_wd xypos2(1) = xypos2(1) + char_ht if (xypos2(0) le !x.window(1) and xypos2(1) ge $ !y.window(0) and xypos2(1) le !y.window(1)) $ then goto, jump2 endfor endelse jump2: y = xypos(1) - (char_ht*.25) ; Move end latitudes around a bit. if (i eq latmax) then y = xypos(1) - (char_ht * .2) if (i eq latmin) then y = xypos(1) ; Find lefthand or righthand side of the plot boundary. if (lhs eq 1) then x = !x.window(0) - (char_wd*.5) + nudgex if (rhs eq 1) then x = !x.window(1) + (char_wd) + nudgex ; Plot latitude label. xyouts, x, y, label, charsize=charsize, color=color, $ align=(lhs eq 1), /norm endif endfor ; i end -- Andrew F. Loughe (afl@cdc.noaa.gov) University of Colorado, CIRES * Campus Box 449 * Boulder, CO 80309 phone: (303) 492-0707 fax: (303) 497-7013