#!/bin/bash
#
# obtain increments from GMT grd file
# $Id: grd2inc,v 1.1 2002-10-21 16:48:10-07 tbecker Exp $
#
mode=${2-1}			# 1: -I/ format 2: just x 3: just y 

tmpd=/tmp/$USER.$HOST.$$.cfg_xxx_2
mkdir $tmpd/
trap "rm -r $tmpd ; exit" 0 1 2 15

if [ -s $1 ];then
    name=$1
else
    if [ -s $1.grd ];then
	name=$1.grd
    else
	echo $1 or $1.grd are nonexistent.
	exit
    fi
fi
cp $name $tmpd
sname=`basename $name`

cd $tmpd
gmtset D_FORMAT %22.15e

if [ $mode -eq 1 ];then
    echo `grdinfo -C $sname | gawk '{printf("-I%022.15e/%022.15e",$8,$9)}' `
elif [ $mode -eq 2 ];then
    echo `grdinfo -C $sname | gawk '{printf("%g",$8)}' `
else
    echo `grdinfo -C $sname | gawk '{printf("%g",$9)}' `
fi

gmtset D_FORMAT %lg
