1REM GMT EXAMPLE 13 2REM 3REM Purpose: Illustrate vectors and contouring 4REM GMT modules: set, grdmath, grdcontour, grdvector, subplot 5REM DOS calls: del 6REM 7gmt begin ex13 8 gmt set FONT_HEADING 40p,Times-Italic 9 gmt grdmath -R-2/2/-2/2 -I0.1 X Y R2 NEG EXP X MUL = z.nc 10 gmt grdmath z.nc DDX = dzdx.nc 11 gmt grdmath z.nc DDY = dzdy.nc 12 gmt subplot begin 2x2 -M0.1c -Ff15c -BWSne -T"z(x,y) = x@~\327@~exp(-x@+2@+-y@+2@+)" 13 gmt grdcontour z.nc -C0.05 -A0.1 -Gd5c -S4 -T+d8p/2p -c0,0 14 gmt grdcontour z.nc -C0.05 -Gd5c -S4 -c0,1 15 gmt grdvector dzdx.nc dzdy.nc -I0.2 -Q0.25c+e+n0.25i+h0.5 -Gblack -W1p -S12c 16 gmt grdcontour dzdx.nc -C0.10 -A0.5 -Gd5c -S4 -T+d8p/2p -c1,0 17 gmt grdcontour dzdy.nc -C0.05 -A0.2 -Gd5c -S4 -T+d8p/2p -c1,1 18 gmt subplot end 19gmt end show 20del z.nc dzdx.nc dzdy.nc 21