Plotting symbols with GMT6 coupe

Q&A
1

Hello,

At the moment I am trying to create a cross-section using coupe in GMT6. Since I don’t want to plot focal mechanisms but just the circles, I am using the -Fsc command. However, there seem to be some problems with that approach.
In the first attempt, trying to keep a common circle size of 0.2c, the first entry will always end up as a circle with a thicker boundary and I am only able to change the boundary thickness of the second and third entry.
In the second attempt, removing the size information from the -Fsc command results in no output of any circle.
I have attached an image showing what I mean and the script I used.
I apologise in case there is an obvious mistake in my script that I just failed to see.
Thank you very much.

GMTquestion
GMTquestion1998×1425 96 KB

Here is my script:

gmt6="/usr/local/opt/gmt@6/bin/gmt"
minlon=10
maxlon=20
max_depth=75
$gmt6 makecpt -Ccool -T0/$max_depth/1 -I -Z > temp_depth.cpt
$gmt6 begin temptest pdf
$gmt6 set GMT_THEME modern
$gmt6 subplot begin 2x1 -Fs10c -Blrtb
$gmt6 subplot set
$gmt6 plot -R$minlon/$maxlon/0/$max_depth -JX15/-4 -: <<- END
> -W.25,-
2.90 $minlon
2.90 $maxlon
END
$gmt6 coupe -Aa$minlon/44.3/$maxlon/45.4/1000/0/${max_depth}f -R$minlon/$maxlon/0/$max_depth -JX15/-4 -Fsc0.2c -W.25p -Ctemp_depth.cpt << END
15.6 45.2 60
16 45.3 50
18 45.5 20
END
$gmt6 subplot end
$gmt6 end show

And the changes in the last lines of the second attempt using individual sizes:

$gmt6 coupe -Aa$minlon/44.3/$maxlon/45.4/1000/0/${max_depth}f -R$minlon/$maxlon/0/$max_depth -JX15/-4 -Fsc -W.25p -Ctemp_depth.cpt << END
15.6 45.2 60 0.3c
16 45.3 50 0.5c
18 45.5 20 0.2c
END

(I have tried the size column without a “c” attached but the result is the same.)

2

I think I found two work-arounds (that are probably not overly elegant, so if anyone has a better solution please let me know):

  1. For some reason the boundary of the first circle is affected by MAP_FRAME_PEN, therefore that can be changed (it will however lead to a thin border around the figure):

$gmt6 subplot begin 2x1 -Fs10c -Blrtb --MAP_FRAME_PEN=0.25p

  1. Introduce the flag to plot focal mechanisms and then just fill the table up with zeros:

$gmt6 coupe -Aa$minlon/44.3/$maxlon/45.4/1000/0/${max_depth}f -R$minlon/$maxlon/0/$max_depth -JX15/-4 -Sa -Fsc -W.25p -Ctemp_depth.cpt << END
15.6 45.2 60 0 0 0 0 0.3c
16 45.3 50 0 0 0 0 0.5c
18 45.5 20 0 0 0 0 0.2c
END

GMTquestion2

3

David, tank you. I had the same problem and I didn’t know how to solve it. But now I follow your solution and it works very well. Thanks, I was stuck with this.