pro xy2ad, x, y, astr, a, d common Broyden_coeff, pv1, pv2 ;Needed for TPV transformation compile_opt idl2 if N_params() LT 4 then begin print,'Syntax -- XY2AD, x, y, astr, a, d' return endif Catch, theError IF theError NE 0 then begin Catch,/Cancel void = cgErrorMsg(/quiet) RETURN ENDIF cd = astr.cd crpix = astr.crpix cdelt = astr.cdelt cd[0,0] *= cdelt[0] & cd[0,1] *= cdelt[0] cd[1,1] *= cdelt[1] & cd[1,0] *= cdelt[1] xdif = x - (crpix[0]-1) ydif = y - (crpix[1]-1) no_PV1 =0 ;Set if PV1 used by TGV distortion if tag_exist(astr,'DISTORT') && astr.distort.name EQ 'SIP' then begin distort = astr.distort a = distort.a b = distort.b na = ((size(a,/dimen))[0]) xdif1 = xdif ydif1 = ydif for i=0,na-1 do begin for j=0,na-1 do begin if a[i,j] NE 0.0 then xdif1 += xdif^i*ydif^j*a[i,j] if b[i,j] NE 0.0 then ydif1 += xdif^i*ydif^j*b[i,j] endfor endfor xdif = TEMPORARY(xdif1) ydif = TEMPORARY(ydif1) ENDIF astr2 = TAG_EXIST(astr,'AXES') ; version 2 astrometry structure xsi = cd[0,0]*xdif + cd[0,1]*ydif ;Can't use matrix notation, in ;case X and Y are vectors eta = cd[1,0]*TEMPORARY(xdif) + cd[1,1]*TEMPORARY(ydif) if tag_exist(astr,'DISTORT') && astr.distort.name EQ 'TPV' then begin pv1 = astr.pv1 pv2 = astr.pv2 result = tpv_eval( [[xsi],[eta]]) xsi = reform( result[*,0] ) eta = reform( result[*,1] ) no_PV1 = 1 ctype = strmid(astr.ctype,0,4) + '-TAN' endif if tag_exist(astr,'DISTORT') && astr.distort.name EQ 'TNX' then begin pv1=astr.distort.lngcor pv2=astr.distort.latcor result = tnx_eval( [[xsi],[eta]]) xsi = reform( result[*,0] ) eta = reform( result[*,1] ) no_PV1 = 1 ctype = strmid(astr.ctype,0,4) + '-TAN' endif if N_elements(ctype) Eq 0 then ctype = astr.ctype crval = astr.crval IF astr2 THEN reverse = astr.reverse ELSE BEGIN coord = strmid(ctype,0,4) reverse = ((coord[0] EQ 'DEC-') && (coord[1] EQ 'RA--')) || $ ((coord[0] EQ 'GLAT') && (coord[1] EQ 'GLON')) || $ ((coord[0] EQ 'ELAT') && (coord[1] EQ 'ELON')) ENDELSE if reverse then begin crval = rotate(crval,2) temp = TEMPORARY(xsi) & xsi = TEMPORARY(eta) & eta = TEMPORARY(temp) endif if strmid(ctype[0],4,1) EQ '-' then begin if no_PV1 then begin ;Set default values for tangent projection pv1 = [0.0d,0,90.0d,180.0d,90.0d] & pv2 = [0.0d,0.0d] endif else begin pv1 = astr.pv1 pv2 = astr.pv2 endelse if astr2 THEN $ WCSXY2SPH, xsi, eta, a, d, CTYPE = ctype[0:1], PV1 = pv1, $ PV2 = astr.PV2, CRVAL = crval, CRXY = astr.x0y0 $ ELSE $ WCSXY2SPH, xsi, eta, a, d, CTYPE = ctype[0:1], PV2 = pv2, $ LONGPOLE = astr.longpole, CRVAL = crval, LATPOLE = astr.latpole endif else begin a = crval[0] + TEMPORARY(xsi) & d = crval[1] + TEMPORARY(eta) endelse return end