NAME

       grd2xyz - Converting a grdfile to an ASCII or binary table


SYNOPSIS

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


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  .gmtde-
       faults  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].

       -L     Indicates  that the x values are longitudes (necessary for -: to
              work).

       -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 out-
              puts all nodes].  Append r to  reverse  the  suppression,  i.e.,
              only output the nodes whose z-value equals NaN.

       -V     Selects verbose mode, which will send progress reports to stderr
              [Default runs "silently"].

       -Z     Write a 1-column ASCII [or binary] table. Output will  be  orga-
              nized  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.

       -O     Selects Overlay plot mode [Default initializes a new  plot  sys-
              tem].   This option only applies to xyz output; see -Z for z ta-
              ble 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(l), gmt(l), grdedit(l), xyz2grd(l)



GMT3.4.6                          1 Jan 2005                        GRD2XYZ(l)

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