# 10. Predefined Bit and Hachure Patterns in GMT

GMT provides 90 different bit and hachure patterns that can be selected with the -Gp or -GP option in most plotting programs. The left side of each image was created using -Gp, the right side shows the inverted version using -GP. These patterns are reproduced below at 300 dpi using the default black and white shades.

Here is the source script for the figure above:

    xwidth=0.45	# Width of each box (all units are in inches)
    ywidth=0.45	# Height of each box
    w=0.9		# Width of two adjacent boxes
    dx=0.50		# Amont to translate to the right
    dy=0.50		# Amount to translate up
    y=0.05		# Initial offset in x
    x=0.05		# Initial offset in y
    back=-5.20	# Amount to translate to left after 1 row

    cat << END > tt.App_E.d
    0	0
    $xwidth	0
    $xwidth	$ywidth
    0	$ywidth
    END

    gmt begin GMT_App_E
    gmt set GMT_THEME cookbook
    gmt basemap -R0/5.75/0/7.55 -Jx1i -B0
    gmt set MAP_FRAME_PEN thinner
    for iy in 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
    do
    	for ix in 1 2 3 4 5 6
    	do
    		let p=iy*6+ix
    		gmt plot -R0/$xwidth/0/$ywidth -Jx1i -Gp$p+r300 tt.App_E.d -X${x}i -Y${y}i -B0
    		gmt plot -GP$p+r300 tt.App_E.d -X${xwidth}i -B0
    		echo "0 0.225" | gmt plot -R0/$w/0/$ywidth -N -Sc0.17i -Wthinnest -Gwhite
    		echo "0 0.225 $p" | gmt text -R0/$w/0/$ywidth -N -F+f9p,Helvetica-Bold
    		y=0.0
    		x=$dx
    	done
    	y=$dy
    	x=$back
    done
    gmt end show