Shading between 2 curves

No particular context :slight_smile:


gmt begin test png

	vecsto=$(gmt math -Q 6 PI MUL =)
	vecste=$(gmt math -Q 1 32 DIV =)

        # x
	gmt math -T$vecsta/$vecsto/$vecste T -o0 = x.txt
       # y = sin(x)
	gmt math -Q x.txt SIN = y.txt 
        #y2 = A cos(x+B)
	gmt math -Q x.txt PI 3 DIV ADD COS 4 PI MUL 10 DIV MUL = y2.txt

        # Shading for red<blue
	gmt math -Q y.txt y2.txt LE 0 NAN y.txt MUL = y_c.txt
        # Shading for red>blue
	gmt math -Q y.txt y2.txt GE 0 NAN y2.txt MUL = y2_c.txt

        # All in one file (for -Sb+base option)
	paste x.txt y.txt y2.txt y_c.txt y2_c.txt > file.txt

	gmt plot file.txt -i0,1 -Wblue -R0/20/-2/2 -JX10c -l"@[\sin(x)@["
	gmt plot file.txt -i0,2 -Wred -l"@[\frac{4\pi}{10}\cos(x+\frac{pi}{3})@["

	gmt plot file.txt -i0,3,2 -Gred@90 -Sb${vecste}q+b -l"red > blue"
	gmt plot file.txt -i0,4,1 -Gblue@90 -Sb${vecste}q+b -l"red < blue"

	gmt basemap -Bxafpigpi -Byafg -BW+t"Relative anomaly" --MAP_FRAME_TYPE=graph
	gmt basemap -Bxapi -BS -Y5c --MAP_FRAME_TYPE=graph
gmt end show

@pwessel : would be nice if there was an option in MAP_FRAME_TYPE to get the x-axis arrow centered at 0 rather than resorting to -Y (which messes up the auto-legend).


update with the new version : (using --MAP_FRAME_TYPE=graph-origin)