map fractional line (x.0 represents pixel center)
      sample         map fractional sample (x.0 represents pixel center)
   
   the call:
   
      <B>status = MTK_LS_TO_SOMXY( mapinfo, line, sample, somx, somy )</B>
   
   returns:
   
      status         0 on success; otherwise failure
      somx           SOM X in meters
      somy           SOM Y in meters

-Examples

      ;;
      ;; Set up input parameters
      ;;
      filename    = '../Mtk_testdata/in/MISR_AM1_GRP_ELLIPSOID_GM_P037_O029058_AA_F