How to get rid of just the map frame?

Q&A
1

We see the black box pointed to by the words MAP_FRAME_PEN.
I want to make that black box disappear, without changing any other
aspects. I.e., I still want ticks and annotations, etc., just not that
black box.

We note 0 means faint and there is no way to say “none.”

--MAP_FRAME_PEN=0,white still gives a thin white line, but I want no line.

Sure,
–MAP_FRAME_WIDTH=0p
alas, my map ins’t a “fancy” map.

Seems that none of these will help me achieve my goal, no matter what I
set them to:

$ gmt defaults|grep MAP_FRAME
MAP_FRAME_AXES                 = WESNZ
MAP_FRAME_PEN                  = thicker,black
MAP_FRAME_PERCENT              = 100
MAP_FRAME_TYPE                 = fancy
MAP_FRAME_WIDTH                = 5p
2

The trick here is to plot the frame line with a white (and preferably fully transparent) line.

3

Thanks, but well, white and even transparency would still be just a trick / hack that fails depending on the background,

20230726T043757
20230726T043757667×556 46.3 KB

or when the image format doesn’t support transparency.

So MAP_FRAME_WIDTH needs to be fixed enhanced so it doesn’t fail on non-fancy maps.

Else it should be called FANCY_MAP_FRAME_WIDTH etc.

4

I use that trick in the Julia wrapper and it works fine.

And please, that abuse of “needs to be fixed” is a bit annoying to say the least.

5

I created https://github.com/GenericMappingTools/gmt/issues/7691 .

6

OK, it is possible:

gmt begin
for i in "g -238" "f 90"
do
    set $i
    gmt basemap -B$1 -R3+uk -JoA-87/42/$2/1:100000
done
gmt end show

g
I got “rid” of the tilted map’s frame.