NAME

      grd2xyz - Converting a grdfile to an ASCII or binary table

SYNOPSIS

      grd2xyz grdfile [ -H[nrec] ] [ -Rwest/east/south/north[r] [ -S ] [
      -Z[flags] ] [ -bo[s] ]

DESCRIPTION

      grd2xyz reads a binary 2-D grdfile and writes out xyz-triplets in
      ASCII [or binary] format to standard output.  Modify the precision of
      the ASCII output format by editing the D_FORMAT parameter in your
      .gmtdefaults file, or choose binary output using single or double
      precision storage.  As an option you may output z-values without the
      (x,y) in a number of formats, see -Z below.

      grdfile
           The 2-D binary file to be converted.

OPTIONS

      -H   Output 1 header record based on information in the grdfile
           header.  Ignored if binary output is selected.  [Default is no
           header].

      -R   west, east, south, and north specify the Region of interest.  To
           specify boundaries in degrees and minutes [and seconds], use the
           dd:mm[:ss] format.  Append r if lower left and upper right map
           coordinates are given instead of wesn.

      -S   Suppress output for nodes whose z-value equals NaN [Default
           outputs all nodes].

      -Z   Write a 1-column ASCII [or binary] table.  Output will be
           organized according to the specified ordering convention
           contained in flags.  If data should be written by rows, make
           flags start with T(op) if first row is y = ymax or B(ottom) if
           first row is y = ymin.  Then, append L or R to indicate that
           first element should start at left or right end of row.  Likewise
           for column formats: start with L or R to position first column,
           and then append T or B to position first element in a row.  For
           gridline registered grids:  If grid is periodic in x but the
           outcoming data should not contain the (redundant) column at x =
           xmax, append x.  For grid periodic in y, skip writing the
           redundant row at y = ymax by appending y.  If the byte-order
           needs to be swapped, append w.  Select one of several data types
           (all binary except a):

                a  ASCII representation
                c  signed 1-byte character
                u  unsigned 1-byte character
                h  short 2-byte integer
                i  4-byte integer
                l  long (4- or 8-byte) integer
                f  4-byte floating point single precision
                d  8-byte floating point double precision

           Default format is scanline orientation of ASCII numbers: -ZTLa.
           Note that -Z only applies to 1-column output.

      -bo  Selects binary output.  Append s for single precision [Default is
           double].  This option only applies to xyz output; see -Z for z
           table output.

EXAMPLES

      To edit individual values in the 5' by 5' hawaii_grv.grd file, try

      grd2xyz hawaii_grv.grd > hawaii_grv.xyz

      To write a single precision binary file without the x,y positions from
      the file raw_data.grd file, using scanline orientation, try

      grd2xyz raw_data.grd -ZTLf > hawaii_grv.b

SEE ALSO

      gmtdefaults, gmt, grdedit, xyz2grd