Hello Sir, I tried to append volcanoes using triangle as the symbol , but it didn’t show as expected. I used
gmt psxy vol_IndianO.txt -R93/109/-17/-1 -JM6i -Sf0.25+t -Gpurple -B4 -W0.2p -K -O > result.ps and
gmt psxy vol_IndianO.txt -R93/109/-17/-1 -JM6i -Stp -Gpurple -B4 -W0.2p -K -O > results.ps and other trials but the triangle to represent my volcanoes on my map didn’t show up. Such as the formal figure
Here is the rough data format
The purple triangle represent volcanoes , how can I adjust my script for this to get this triangles on my map
Many thanks