NAME
    xw84t / xw84td - From World Geodetic System to Tokyo Datum
    xtw84 / xtw84d - From Tokyo Datum to World Geodetic System
      after Kanazawa(1988): "Calculation formula for the relationship between
      WGS-84 and Tokyo Datum indicated on Japanese charts. Data Rept. Hydrogr.
      Obs., Ser. Satellite Geodesy, no.1, 76-81".

SYNOPSIS

      call xw84t (wlat,  wlon,  walt,  tlat,  tlon,  talt)
      call xw84td(dwlat, dwlon, dwalt, dtlat, dtlon, dtalt)
  wlat, wlon  [float]   WGS Lat. and Lon. (in minutes) to be converted
  dwlat,dwlon [double]   [ditto]
  walt        [float]   WGS altitude (in m) to be converted
  dwalt       [double]   [ditto]
  tlat, tlon  [float]   Calculated results.
                        Tokyo Datum Lat. and Lon. (in minutes) are given.
  dtlat,dtlon [double]   [ditto]
  talt        [float]   Calculated result.
                        Tokyo Datum altitude (in m) is given.
  dtalt       [double]   [ditto]

      call xtw84 (tlat,  tlon,  talt,  wlat,  wlon,  walt)
      call xtw84d(dtlat, dtlon, dtalt, dwlat, dwlon, dwalt)
  tlat, tlon  [float]   Tokyo Datum Lat. and Lon. (in minutes) to be converted
  dtlat,dtlon [double]   [ditto]
  talt        [float]   Tokyo Datum altitude (in m) to be converted
  dtalt       [double]   [ditto]
  wlat, wlon  [float]   Calculated results.
                        WGS Lat. and Lon. (in minutes) are given.
  dwlat,dwlon [double]   [ditto]
  walt        [float]   Calculated result. WGS altitude (in m) is given.
  dwalt       [double]   [ditto]