uint8 datatype issue

[De-Guo]

Description of the problem

I read an image of uint8 datatype with rioxarray.open_rasterio and plot with pygmt raise errors.

If I convert datatype to float, my script runs fluently.

Full error message

Traceback (most recent call last):
  File "C:\ProgramData\Anaconda3\lib\site-packages\IPython\core\interactiveshell.py", line 3552, in run_code
    exec(code_obj, self.user_global_ns, self.user_ns)
  File "<ipython-input-2-cbda221bbf05>", line 1, in <module>
    runfile('D:/NutSync/code/funcs_lib_dg/plot_func/plot_raster_pygmt.py', wdir='D:/NutSync/code/funcs_lib_dg/plot_func')
  File "C:\Program Files\JetBrains\PyCharm 2020.1\plugins\python\helpers\pydev\_pydev_bundle\pydev_umd.py", line 197, in runfile
    pydev_imports.execfile(filename, global_vars, local_vars)  # execute the script
  File "C:\Program Files\JetBrains\PyCharm 2020.1\plugins\python\helpers\pydev\_pydev_imps\_pydev_execfile.py", line 18, in execfile
    exec(compile(contents+"\n", file, 'exec'), glob, loc)
  File "D:/NutSync/code/funcs_lib_dg/plot_func/plot_raster_pygmt.py", line 307, in <module>
    xrd = main()
  File "D:/NutSync/code/funcs_lib_dg/plot_func/plot_raster_pygmt.py", line 301, in main
    rastr_plot.plot_raster_grid(figname=figname)
  File "D:/NutSync/code/funcs_lib_dg/plot_func/plot_raster_pygmt.py", line 99, in plot_raster_grid
    cmap=cpt
  File "C:\ProgramData\Anaconda3\lib\site-packages\pygmt\helpers\decorators.py", line 586, in new_module
    return module_func(*args, **kwargs)
  File "C:\ProgramData\Anaconda3\lib\site-packages\pygmt\helpers\decorators.py", line 726, in new_module
    return module_func(*args, **kwargs)
  File "C:\ProgramData\Anaconda3\lib\site-packages\pygmt\src\grdimage.py", line 173, in grdimage
    fname = stack.enter_context(file_context)
  File "C:\ProgramData\Anaconda3\lib\contextlib.py", line 427, in enter_context
    result = _cm_type.__enter__(cm)
  File "C:\ProgramData\Anaconda3\lib\contextlib.py", line 112, in __enter__
    return next(self.gen)
  File "C:\ProgramData\Anaconda3\lib\site-packages\pygmt\clib\session.py", line 1341, in virtualfile_from_grid
    self.put_matrix(gmt_grid, matrix)
  File "C:\ProgramData\Anaconda3\lib\site-packages\pygmt\clib\session.py", line 895, in put_matrix
    raise GMTCLibError(f"Failed to put matrix of type {matrix.dtype}.")
pygmt.exceptions.GMTCLibError: Failed to put matrix of type uint8.

System information

I use pygmt 0.5.0 with python 3.7.

[seisman]

@De-Guo Thanks for your issue report.

I'm working on PR #1963, which should fix the issue. It would be great if you can try that PR to see if it works for you.

To install PyGMT in that branch, you can use:

pip install https://github.com/GenericMappingTools/pygmt/archive/refs/heads/add-datatypes.zip

[De-Guo]

Thanks, @seisman !
I got a sense of what the problem is.

[De-Guo]

I havenot test the add-datatypes branch due to my python version.
ERROR: Package 'pygmt' requires a different Python: 3.7.10 not in '>=3.8

[seisman]

Unfortunately, we no longer support Python <= 3.7.

[seisman]

FYI, I have merged the PR into main branch.

[De-Guo]

Thanks for mention!