Is it possible to multiply varibles in gmt movie, or other modules?

Q&A
1

I am trying to multiply variable ${MOVIE_FRAME} by some factor, let’s say 10.

I’ve taken the example from the cookbook which produces 360 images when run with gmt movie:

gmt begin globe1
gmt pscoast -Rg -JG${MOVIE_FRAME}/20/${MOVIE_WIDTH} -Gtan -Slightblue -A700 -Bg -X0 -Y0
gmt end show

Is it possible to multiple variable MOVIE_FRAME by 10 for example, and reduce the number of frames produced to 36?

using:

gmt movie globe.sh -Nglobe -T36 -Agif -C6ix6ix100

instead of

gmt movie globe.sh -Nglobe -T360 -Agif -C6ix6ix100

If I append 10* after -JG in the script it will plot 360 frames centered at longitude 5E, rather than 10, 20, 30…

2

The -Tframes is only used for the simplest of cases where you can just use $MOVIE_FRAME directly in your script as an integer. For anything more tricky you simply create a table with what values you want, e.g.

gmt movie -T0/360/5

and now you need to use $MOVIE_COL0 instead to access the longitude. For more fancy stuff you would make a table with gmt math and feed it via -T.

3

Thank you very much, worked a treat!