if(n_elements(old) eq 0) then begin ;{ filenm='980226_181126_eclp.fts' old = readfits(filenm,hdr, SILENT=1) filenm='980226_181427_eclp.fts' new = readfits(filenm,hdr, SILENT=1) byteorder,old byteorder,new ;; Convert the signed integers to unsigned integers. imgN = float(new) imgN = (imgN lt 0.) * ( imgN + 2.*32768. ) + (imgN ge 0.)*(imgN) imgO = float(old) imgO = (imgO lt 0.) * ( imgO + 2.*32768. ) + (imgO ge 0.)*(imgO) window,xsize=2034,ysize=2034,xpos=-400,ypos=-400 diff = imgN-imgO endif ;} mn= -5. mx= 5. tv,bytscl(diff, mn,mx) xbeg= 535 & ybeg= 661 xend= 733 & yend= 841 leastsq,imgN(xbeg:xend,ybeg:yend),imgO(xbeg:xend,ybeg:yend),aa,bb,RR print,aa,bb,RR window,1 plot,imgN(xbeg:xend,ybeg:yend),imgO(xbeg:xend,ybeg:yend) end