# How to rotate colorbar labels in PyGMT? **URL:** \ **Category:** PyGMT Q&A\ **Created:** [September 24, 2024, 7:44pm UTC](https://forum.generic-mapping-tools.org/t/how-to-rotate-colorbar-labels-in-pygmt/5381 "2024-09-24T19:44:20Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![msc](https://avatars.discourse-cdn.com/v4/letter/m/f6c823/32.png) [@msc](https://forum.generic-mapping-tools.org/u/msc)\ **Post date:** [September 24, 2024, 7:44pm UTC](https://forum.generic-mapping-tools.org/t/how-to-rotate-colorbar-labels-in-pygmt/5381/1 "2024-09-24T19:44:20Z")
Hi everyone! First time posting here. I’m trying to rotate the labels in the colorbar with pygmt. I tried adding -S option from GMT doc and adding +a45 to the position and frame variables in pygmt but no success. ```auto # Add a colorbar for the elevation fig.colorbar( # Place the colorbar outside the plot (upper-case "J") # Move the x label above the horizontal colorbar ("+ml") position = ["JMR+o1c/-0.1c+w14c/0.4c+ml"], # Add a box around the colobar with a fill ("+g") in "white" color and # a transparency ("@") of 8 % box="+gwhite@8", # Add x and y labels ("+l") frame=["xa2000f1000","x+lElevation", "y+lm"], ) ``` ![Screenshot 2024-09-24 at 12.31.38 PM](https://canada1.discourse-cdn.com/flex047/uploads/gmt/original/2X/2/2bf3dafe4e2907fc5d326e2a5dca02624f26b6ab.png) I would like to rotate the labels/annotations so that they are plotted parallel to the colorbar, if possible. ---
**Author:** ![yvonnefroehlich](https://yyz1.discourse-cdn.com/flex047/user_avatar/forum.generic-mapping-tools.org/yvonnefroehlich/32/5064_2.png) [@yvonnefroehlich](https://forum.generic-mapping-tools.org/u/yvonnefroehlich)\ **Post date:** [September 24, 2024, 9:49pm UTC](https://forum.generic-mapping-tools.org/t/how-to-rotate-colorbar-labels-in-pygmt/5381/2 "2024-09-24T21:49:20Z")
Hello @msc, Welcome to the GMT forum 🙂. I just tried a simple code example. Here, appending **+a** to the frame parameter of `Figure.colorbar` works. Maybe this example can already help you to adjust your code. Otherwise please post your code, in which you try to rotate the annotations of the colorbar. ```python import pygmt size = 5 fig = pygmt.Figure() fig.basemap(region=[-size, size] * 2, projection=f"X{size*2}c", frame=0) fig.colorbar(cmap="batlow", position="jMC+o-3c/0+ml", frame="xaf+lElevation") fig.colorbar(cmap="batlow", position="jMC+ml", frame="xaf+a45+lElevation") fig.colorbar(cmap="batlow", position="jMC+o3c/0c+ml", frame="xaf+a90+lElevation") fig.show() ``` ![colorbar_rotate_annotations](https://canada1.discourse-cdn.com/flex047/uploads/gmt/original/2X/3/34cc72a972f32a84c0d0a21344de8a3673106bad.png) ---
**Author:** ![msc](https://avatars.discourse-cdn.com/v4/letter/m/f6c823/32.png) [@msc](https://forum.generic-mapping-tools.org/u/msc)\ **Post date:** [September 25, 2024, 5:32pm UTC](https://forum.generic-mapping-tools.org/t/how-to-rotate-colorbar-labels-in-pygmt/5381/3 "2024-09-25T17:32:37Z")
Thank you so much @yvonnefroehlich! Yes, I was able to make it work by modifying the basemap projection. If I use a geographic projection: ```auto fig.basemap(region=[115, 119.5, 4, 7.5], projection="M15c", frame=["ag", "WsNe"] ) ``` then I get this error that I was not addressing before: ```auto colorbar [ERROR]: Option -B: Cannot use +a for geographic basemaps colorbar [ERROR]: Option -B parsing failure. Correct syntax: colorbar [ERROR]: Offending option -Bxaf+a90+lElevation ``` ---
**Author:** ![yvonnefroehlich](https://yyz1.discourse-cdn.com/flex047/user_avatar/forum.generic-mapping-tools.org/yvonnefroehlich/32/5064_2.png) [@yvonnefroehlich](https://forum.generic-mapping-tools.org/u/yvonnefroehlich)\ **Post date:** [September 25, 2024, 6:45pm UTC](https://forum.generic-mapping-tools.org/t/how-to-rotate-colorbar-labels-in-pygmt/5381/4 "2024-09-25T18:45:52Z")
Yes, that’s true. Rotated anntotations are only available for Carthesian plots ([4. Standardized command line options — GMT 6.7.0 documentation](https://docs.generic-mapping-tools.org/dev/reference/options.html#axes-settings)). And it looks like this applies not only the the frame of the figure or map, but also for the frame of the colorbar. So far, I only have a very rude work around. There, the projection is changed to Cartesian before plotting the colorbar. Playing around with `Figure.shift_origin` can be also helpful. ```python import pygmt fig = pygmt.Figure() # Basemap with none Cartesian projection fig.basemap(region=[115, 119.5, 4, 7.5], projection="M15c", frame=True) # !!! This is not a nice solution !!! # !!! Be aware of that the projection changes now !!! # First plot the map frame in red to adjust the size of the Cartesian projection #with pygmt.config(MAP_FRAME_PEN="red"): # In the end make the frame completely transparent (@100) to hide it with pygmt.config(MAP_FRAME_PEN="red@100"): # We need a basemap with a Cartesian projection to be allowed to rotate # the annotations of the colorbar # The size of this projection is manually adjusted based on the width and # height of the projection used for the map at the beginning fig.basemap(region=[-1, 1] * 2, projection="X15c/11.5c", frame=0) fig.colorbar(cmap="batlow", position="JRM+ml+w10c/0.4c", frame="xaf+a90+lElevation") # !!! Every data you plot now is plotted with a Cartesian projection !!! fig.show() ``` ![colorbar_none_cartesian_rotated_annotations](https://canada1.discourse-cdn.com/flex047/uploads/gmt/original/2X/b/baac0b0667c1ea7b8e2ff36975aee377af1e0538.png) ---
**Author:** ![msc](https://avatars.discourse-cdn.com/v4/letter/m/f6c823/32.png) [@msc](https://forum.generic-mapping-tools.org/u/msc)\ **Post date:** [September 25, 2024, 7:39pm UTC](https://forum.generic-mapping-tools.org/t/how-to-rotate-colorbar-labels-in-pygmt/5381/5 "2024-09-25T19:39:10Z")
Yes, I also did a not so pretty work around, but this is helpful, thanks again!