Plot3d : what am I doing wrong?

Q&A
1

Hi there,
I’m trying to create a scatter plot of hypocentre underneath a volcanic structure.
I tried to play with plot3d but it keeps failing.
At first I used a .csv with -i for lon/lat/depth : nothing
Then I used awk to create a text file with just lon/lat/depth : still nothing

gmtinfo [ERROR]: No data columns to work with - exiting
gmtinfo [ERROR]: Data file only has trailing text. GMT expects numerical columns followed by optional trailing text
[Session gmt (0)]: Error returned from GMT API: GMT_OBJECT_NOT_FOUND (60)

Finally I injected the coordinates directly in-line to no avail, only 1 point is shown.

gmt plot3d -Ra -JM10c -JZ1c -Sc0.1c -Gred -Bafg -p210/30 -png test << EOF
-60.638500 14.052167 6.36
-60.558833 15.332167 30.0
-62.130833 17.402000 46.0
-61.890667 16.472167 150.51
-61.902333 17.504500 0.0
-60.722167 15.989667 29.08
-61.173667 15.327667 140.55
-62.981667 17.400167 169.77
EOF

Is it some kind of bug or my data are not in the correct formatting ?

And is it possible to have small sphere (not a focal mechanism) instead of a flat circle ?

gmt --version : 6.5.0_ffc5eba_2022.09.14

2

I suspect that -Ra only reads the X and Y values of your data. Try this instead -R-63/-60/14/17/0/170 .

test
test303×994 4.56 KB

3

Alright alright … Thanks @Esteban82. I’ll open an issue or a feature request on github.

@pwessel : should I open another one for the sphere symbol too?

4

The (lack of) spheres is a known issue, awaiting for its time (need a PostScript solution)

5

would a custom symbol help? Or would it be flattened too with perspective?
Why are we able to plot “earth” as a 3D sphere and not a symbol ?

6

I guess yes. If the symbol is made of a grdview of a triangulated surface then yes, but it would be terribly inefficient.

We don’t have Earth as a sphere, do we?

7

Not exactly through -p perspective … but… I mean … there’s curvature!

8

The disks (circles) are curved too :slight_smile:

9

Fair enough :sweat_smile: