... IDL procedure to display ; a) a region of spectrum , together with a fit , if supplied, ; b) positions and relative strengths (gf or W_lambda) of lines in ; common atomic spectra may be marked in the lower panel. ; c) lines of sleceted atoms are identified in the top panel ; ; Command arguments: ; specfile - character string - name of file containing spectrum (and fit ) ; assumed to be x,y file with 3- ... Assesses lines in linelist by the strength values "listfr". ...