grdedit

       grdedit - Modifying the header in a 2-D grdfile

SYNOPSIS

       grdedit  grdfile  [  -A ] [ -Dxunit/yunit/zunit/scale/off­
       set/title/remark ] [ -Rwest/east/south/north[r] ] [ -S ] [
       -V ]

DESCRIPTION

       grdedit  reads the header information in a binary 2-D grd­
       file and replaces the information with values provided  on
       the command line [if any]. As an option, global, geograph­
       ical grids (with  360  degrees  longitude  range)  can  be
       rotated  in the east-west direction. grdedit only operates
       on files containing a grdheader.
               No space between the option flag and  the  associ­
       ated  arguments.  Use  upper case for the option flags and
       lower case for modifiers.

       grdfile
              Name of the 2-D grdfile to modify

OPTIONS

       -A     If necessary, adjust the file's x_inc, y_inc to  be
              compatible  with  its  domain  (or a new domain set
              with -R).  Older gridfiles (i.e., created prior  to
              GMT  3.1) often had excessive slop in' x_inc, y_inc
              and an adjustment is  necessary.  Newer  files  are
              created correctly.

       -D     Give  new  values  for  xunit, yunit, zunit, scale,
              offset, title, and remark.  To leave  some  of  the
              values untouched, specify = as the new value.

       -R     west,  east, south, and north specify the Region of
              interest. To specify boundaries in degrees and min­
              utes  [and  seconds],  use  the  dd:mm[:ss] format.
              Append r if lower left and upper right map  coordi­
              nates  are  given instead of wesn.  The new w/e/s/n
              values will replace those  in  the  grid,  and  the
              x_inc, y_inc values are adjusted, if necessary.

       -S     For  global,  geographical  grids only. Grid values
              will be shifted laterally according to the new bor­
              ders given in -R.

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

EXAMPLES

       Let  us  assume  the  file  data.grd   covers   the   area
       300/310/10/30.  We  want  to  change  the  boundaries from

       grdedit   data.grd   -R-60/-50/10/30  -D=/=/=/=/=/"Gravity
       Anomalies"/=

       The grid world.grd has the limits 0/360/-72/72.  To  shift
       the data so that the limits would be -180/180/-72/72, use

       grdedit world.grd -R-180/180/-72/72 -S

       The file junk.grd was created prior to GMT 3.1 with incom­
       patible -R and -I arguments. To reset the x- and  y-incre­
       ments we run

       grdedit junk.grd -A

SEE ALSO

       gmt(l), grd2xyz(l), xyz2grd(l)