# Geographic Basemap - Axes Annotation Orientation

**URL:** <https://forum.generic-mapping-tools.org/t/geographic-basemap-axes-annotation-orientation/259>\
**Category:** Q&A\
**Created:** [February 22, 2020, 12:09am UTC](https://forum.generic-mapping-tools.org/t/geographic-basemap-axes-annotation-orientation/259 "2020-02-22T00:09:02Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![Wally](https://avatars.discourse-cdn.com/v4/letter/w/9de053/32.png) [@Wally](https://forum.generic-mapping-tools.org/u/Wally)\
**Post date:** [February 22, 2020, 12:09am UTC](https://forum.generic-mapping-tools.org/t/geographic-basemap-axes-annotation-orientation/259/1 "2020-02-22T00:09:02Z")

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I am creating a map using the Oblique Mercator projection. The labelling of the axes looks like this:

 ![Long180](https://canada1.discourse-cdn.com/flex047/uploads/gmt/original/1X/fdcb44a6a6a6dc8fc53380991c73923ee62622db.png)

I want to rotate the Longitude annotations by 180°, so that they are more readable. Is that possible? I’ve looked at -B+a, but that doesn’t work for geographic basemaps. I’ve also looked at MAP\_ANNOT\_ORTHO, but that has no effect either.

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**Author:** ![pwessel](https://yyz1.discourse-cdn.com/flex047/user_avatar/forum.generic-mapping-tools.org/pwessel/32/30_2.png) [@pwessel](https://forum.generic-mapping-tools.org/u/pwessel)\
**Post date:** [February 22, 2020, 12:24am UTC](https://forum.generic-mapping-tools.org/t/geographic-basemap-axes-annotation-orientation/259/2 "2020-02-22T00:24:43Z")

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Can you send the psbasemap command that makes the frame please? See MAP\_ANNOT\_OBLIQUE for various options.

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**Author:** ![Wally](https://avatars.discourse-cdn.com/v4/letter/w/9de053/32.png) [@Wally](https://forum.generic-mapping-tools.org/u/Wally)\
**Post date:** [February 22, 2020, 12:30am UTC](https://forum.generic-mapping-tools.org/t/geographic-basemap-axes-annotation-orientation/259/3 "2020-02-22T00:30:39Z")

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Basemap command is:

psbasemap -Ba10g5 -JOA133.1/-2.7/143.95/500 -Rn-2600/2600/-800/800 -O -K \>\> %ps%

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**Author:** ![pwessel](https://yyz1.discourse-cdn.com/flex047/user_avatar/forum.generic-mapping-tools.org/pwessel/32/30_2.png) [@pwessel](https://forum.generic-mapping-tools.org/u/pwessel)\
**Post date:** [February 22, 2020, 12:47am UTC](https://forum.generic-mapping-tools.org/t/geographic-basemap-axes-annotation-orientation/259/4 "2020-02-22T00:47:04Z")

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Thanks, looks like GMT4 syntax to me. Anyway, something like this

`gmt psbasemap -Ba10g5 -JOA133.1/-2.7/143.95/9i -R-2600/2600/-800/800+un --FORMAT_GEO_MAP=dddF --MAP_ANNOT_OBLIQUE=0 > t.ps`

avoids the overprinting. There should never be a need to rotate by 180 unless you are also rotating the figure after it is made. All the annotations above are readable and not backward.

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**Author:** ![Wally](https://avatars.discourse-cdn.com/v4/letter/w/9de053/32.png) [@Wally](https://forum.generic-mapping-tools.org/u/Wally)\
**Post date:** [February 22, 2020, 12:54am UTC](https://forum.generic-mapping-tools.org/t/geographic-basemap-axes-annotation-orientation/259/5 "2020-02-22T00:54:32Z")

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Thanks for that Paul. You have actually revealed the underlying problem and that is I am rotating the figure 90° after it is made. The oblique equator is parallel to the x- axis and I want it to be parallel to the y-axis, hence the 90° rotation. I’ve asked the question about that in a separate post.  
Thanks for the prompt reply.