.TH GRDEDIT l DATE
.SH NAME
grdedit \- Modifying the header in a 2-D grdfile
.SH SYNOPSIS
\fBgrdedit\fP \fIgrdfile\fP [\fB\-D\fP\fIxunit/yunit/zunit/scale/offset/title/remark\fP] 
[ \fB\-R\fP\fIwest/east/south/north\fP[\fIr\fP] ] [\fB\-S\fP ]
.SH DESCRIPTION
\fBgrdedit\fP 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.  \fBgrdedit\fP only operates on files containing a grdheader.
.br
	No space between the option flag and the associated arguments.  Use upper case for the
option flags and lower case for modifiers.
.TP
\fIgrdfile\fP
Name of the 2-D grdfile to modify
.sp
.SH OPTIONS
.TP
.B \-D
Give new values for \fIxunit, yunit, zunit, scale, offset, title,\fP and \fIremark\fP.
To leave some of the values untouched, specify = as the new value.
#include "explain_-R.txt"
.TP
.B \-S
For global, geographical grids only.  Grid values will be shifted laterally according to
the new borders given in \fB\-R\fP.
.SH 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
.br
.sp
grdedit data.grd \fB\-R\fP-60/-50/10/30 \fB\-D\fP=/=/=/=/=/"Gravity Anomalies"/=
.br
.sp
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
.br
.sp
grdedit world.grd \fB\-R\fP-180/180/-72/72 \fB\-S\fP
.SH SEE ALSO
gmt, grd2xyz, xyz2grd
#include "refs.i"
