Plotting star maps with GMT: is it possible specify 24 h range för X coordinates?

Added by Hernán over 1 year ago

Hello GMT'ers,

I am using GMT to plot star (sky) maps. Everything that is important works fine and the resulting maps are both useful and elegant.

My only difficulty is merely aesthetical and has to do with finding a way to annotate the X coordinates as right ascension, that is, in the 24 hour range instead of the (reversed) 360 degree range. As far as I understand the documentation the 24 hour range works for time in the -Jxy projection type but not with geographic corrdinates the stereographic projection that I use. I have combed the documentation but have not been able to come up with a suitable solution (and yes, I have searched the internet as well). A thought I had is that it could be ideal if there would be a way of specifying a custom range in psbasemap, such as it will "map" (i.e. transform) the annotation coordinates from the given coordinate range in the data to another custom range, but I understand no such a thing exists.

Has anyone solved this problem before? If so, could you please describe how?

Thanks in advance and also thanks to all contributors for this superb tool!

Hernán

Leo-R_finder_17.png - R Leo (25.5 KB)


Replies (3)

RE: Plotting star maps with GMT: is it possible specify 24 h range för X coordinates? - Added by Joaquim over 1 year ago

For the moment I don't see any alternative than to use custom annotations. See example this in CookBook https://www.generic-mapping-tools.org/gmt/latest/GMT_Docs.html#custom-axes

RE: Plotting star maps with GMT: is it possible specify 24 h range för X coordinates? - Added by Hernán over 1 year ago

That option looks very promising! I will have a deeper look at that.

Thank you!

RE: Plotting star maps with GMT: is it possible specify 24 h range för X coordinates? - Added by Hernán over 1 year ago

The custom annotation option did the job! Thank you again!

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