Psxy -SE option ellipse axis units

Q&A
1

Hi! I am using GMT 5.4.0 and trying to plot an ellipse as a symbol using psxy and an ellipse gets plotted if I’m using -Se option, but nothing seems to be plotted when using -SE option.
I want to use -SE since that’s the one to use with geographical coordinats, and my semi-major and semi-minor axis are in degrees and the angle is an azimuth.

My file consists of 1) lon 2) lat 3) azumith of the semi-major axis 4) semi-major axis 5) semi-minor axis
-84.5 -16.5 30.5 0.2 0.1 12.5

I scale the ellipse 10 times so it should be 2 degrees and 1 degree for the axis lengths.

awk '{print $1,$2,$3,10*$4,10*$5}' file1 | psxy -R-94/-75/-19/-11 -JR0/16c -Ba5g1/a2g1WsNE -SE -W0.5 -P -K -O

I am guessing that there is problem with the way I’ve set units. Could someone tell me what the problem could be and/or how to set the units correctly?

2

The default unit for axis length is km. So you can use either

awk '{print $1,$2,$3,10*$4*111.2,10*$5*111.2}'

or

awk '{print $1,$2,$3,10*$4"d",10*$5"d"}'
1 Like
3

Thanks I used the second suggestion with adding “d” and that worked!
I didn’t use the first one since I will have more points which will be on different latitudes.