Map spanning across two subplots

Hello GMT family,
I want to draw three auto-tagged maps in a 2x2 subplot, such that the first map spans across the upper half of the figure. So, my figure should be something like an up-down flip of the one on the right. Can someone kindly help me out? Thanks very much.
This is the script I used:

gmt begin QQQ png
	gmt subplot begin 2x2 -A+JTL+o-0.15i/0.07i -Fs6.2i/3i -M0i/0.3i -Rd -JH13.5c -Bxa60 -Bya0
		gmt subplot set 0:1 -A"a)"
		gmt coast -A3000 -Gpeachpuff4 -Dh -Wthinnest  -Slightblue
		gmt subplot set 2 -A"b)"
		gmt coast -A3000 -Ggray60 -Dh -Wthinnest  -Sazure1
		gmt subplot set 3 -A"c)"
		gmt coast -A3000 -Gdarkbrown -Dh -Wthinnest  -Sgray72
	gmt subplot end
gmt end show 

I’m interested too.
Maybe using -Ff instead of -Fs, then a 2x2 mapping except one is twice as wide (and there’s no fourth)?

The GMT China community provides an example that is almost exactly what you need.

The example plots Cartesian frames but it also works for geographic maps. The key point in this example is that you need to call subplot begin twice because GMT doesn’t support nested subplot yet.

1 Like

Hello @seisman, thank you very much for the response. I will try it out.

Hi @milton, I think you will need to use both -Ff and -Fs if you want geographic maps. Based on the answer from @seisman, this is what I’ve done:

gmt begin QQQ png		
	gmt subplot begin 1x2 -A+JTL+o0i/-0.1i -Fs6.2i/3i -M0.15i/0i	
		gmt subplot set 0,0 -A"b)"
			gmt coast -A3000 -Gpeachpuff4 -Df -Wthinnest -Slightblue -Rd -JH13.5c -Bxa60 -Bya0 
						
		gmt subplot set 0,1 -A"c)"
			gmt set FONT_ANNOT_PRIMARY 8p,Helvetica,black
			gmt set MAP_GRID_PEN_PRIMARY 0.01p,gray			
			gmt basemap -JX6.5c/7.0c -R-300/300/0/6 -Bxa100g100+l"x-axis" -Bya1g0.5f0.5+l"y-axis"
	gmt subplot end


	gmt subplot begin 1x1 -A+JTL+o0i/-0.2i -Ff6.2i/5i -M0.0i/0.05i -Bxa60 -Bya0 -Yh+1.7c
		gmt subplot set 0,0 -A"a)"	
		gmt coast -A3000 -Gpeachpuff4 -Sazure -Df -Wthinnest -JH0/24c -Rd 			
						
	gmt subplot end

gmt end show