How do I create a custom colormap that’s a continuous gradient between two colors?
For example, I want the bottom of the scale to be a mid-gray color and the top to be black.
This seems like it might work. gmt makecpt -C80/80/80,0/0/0 -T0/1 -Fr -N
0 80/80/80 1 0/0/0 L
However, when I do something like this is pygmt, it acts like no colormap is employed. pygmt.makecpt(color_model='r',cmap='80/80/80,0/0/0',series='0/1',no_bg=True)
I’m trying to show “mountains” by filtering relief data by elevation and then drawing it with something like:
If I use one of the standard colormaps (e.g. ‘geo’, ‘gray’, …) it does what I’d expect (though using a colormap I don’t want).
I probably don’t understand colormap creation properly, but I’m not sure what I’m doing wrong. How can I accomplish this?
i think it’s not, pygmt.makecpt() generates an identical .cpt file using H/output option.
more likely
don’t understand colormap creation properly
e.g. -T0/1 specifies range of altitudes/Z coordinate of 0 to1 (meters or whatever topicstarter’s data is)
for altitudes the range of 0 to 1 is not gonna work, unless the user knows exactly what he/she is doing.
Does gridimagehave to apply a color to every point? What can I do to the relief data in order to display “nothing” for a given position? (I’m trying to create “layers” for this map.)