GRDEDIT(l)																GRDEDIT(l)

NAME

       grdedit - Modifying the header in a 2-D grdfile

SYNOPSIS

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

DESCRIPTION

       grdedit	reads  the  header  information  in a binary 2-D grdfile and replaces the information with values provided on the command line [if
       any]. As an option, global, geographical 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 associated 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  cor-
	      rectly.

       -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 minutes  [and  seconds],  use  the
	      dd:mm[:ss]  format.  Append  r if lower left and upper right map coordinates 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 borders 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 geodetic longitudes to geographic  and
       put a new title in the header. We accomplish this by

       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 incompatible -R and -I arguments. To reset the x- and y-increments we run

       grdedit junk.grd -A

SEE ALSO

       gmt(1gmt), grd2xyz(1gmt), xyz2grd(1gmt)

								    1 Jan 2004								GRDEDIT(l)