PyGMT fig.tilemap() error: grdimage [ERROR]: Byte image without indexed color requires a CPT via -C

Q&A PyGMT Q&A
1

script to reproduce:

import pygmt
fig = pygmt.Figure()
fig.tilemap(
    #region=[-63.6833, -63.5667, 44.65, 44.7333],
    region=[-7088268.57626, -7078991.95203, 5567892.48683, 5579637.51917],
    #projection="EPSG:3857",
    lonlat=False,
    projection="x1:50000",
    # Set level of details (0-22)
    # Please note, not all zoom levels are always available
    zoom=14,
    # Use tiles from OpenStreetMap tile server
    source="https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png",
)
fig.savefig("tilemap_EPSG3857.png")

error messages:

Traceback (most recent call last):
  File "/home/mkononets/GIS data/Bedford Basin/test_pygmt_tilemap_BB.py", line 3, in <module>
    fig.tilemap(
  File "/home/mkononets/mambaforge/envs/pygmt/lib/python3.11/site-packages/pygmt/helpers/decorators.py", line 598, in new_module
    return module_func(*args, **kwargs)
  File "/home/mkononets/mambaforge/envs/pygmt/lib/python3.11/site-packages/pygmt/helpers/decorators.py", line 738, in new_module
    return module_func(*args, **kwargs)
  File "/home/mkononets/mambaforge/envs/pygmt/lib/python3.11/site-packages/pygmt/src/tilemap.py", line 148, in tilemap
    lib.call_module(
  File "/home/mkononets/mambaforge/envs/pygmt/lib/python3.11/site-packages/pygmt/clib/session.py", line 628, in call_module
    raise GMTCLibError(
pygmt.exceptions.GMTCLibError: Module 'grdimage' failed with status code 79:
grdimage [ERROR]: Byte image without indexed color requires a CPT via -C

pygmt.show_versions():

PyGMT information:
  version: v0.10.0
System information:
  python: 3.11.4 | packaged by conda-forge | (main, Jun 10 2023, 18:08:17) [GCC 12.2.0]
  executable: /home/mkononets/mambaforge/envs/pygmt/bin/python3.11
  machine: Linux-5.15.0-53-generic-x86_64-with-glibc2.35
Dependency information:
  numpy: 1.25.2
  pandas: 2.0.3
  xarray: 2023.7.0
  netCDF4: 1.6.4
  packaging: 23.1
  contextily: 1.3.0
  geopandas: 0.13.2
  IPython: 8.14.0
  rioxarray: 0.14.1
  ghostscript: 10.02.0
GMT library information:
  binary version: 6.5.0_5496e05_2023.10.05
  cores: 4
  grid layout: rows
  image layout: 
  library path: /home/mkononets/mambaforge/envs/pygmt/lib/libgmt.so
  padding: 2
  plugin dir: /home/mkononets/mambaforge/envs/pygmt/lib/gmt/plugins
  share dir: /home/mkononets/mambaforge/envs/pygmt/share/gmt
  version: 6.5.0
2

Hm, recent changes related to grdimage which might be after your Oct 5 master. If you can, update gmt master and let us know if the same error

3

Thanks! I will certainly update and test, once the updated gmt 6.5.0 conda packages are available.

4

downgrade to gmt 6.4.0 solved this issue, tilemap is generated as expected.

5

there’s finally gmt-6.5.0.dev9+0776994-h5cae338_1.conda available, with this build the issue seems gone for good

PyGMT information:
  version: v0.10.0
System information:
  python: 3.11.4 | packaged by conda-forge | (main, Jun 10 2023, 18:08:17) [GCC 12.2.0]
  executable: /home/mkononets/mambaforge/envs/pygmt/bin/python3.11
  machine: Linux-5.15.0-53-generic-x86_64-with-glibc2.35
Dependency information:
  numpy: 1.25.2
  pandas: 2.0.3
  xarray: 2023.7.0
  netCDF4: 1.6.5
  packaging: 23.1
  contextily: 1.3.0
  geopandas: 0.13.2
  IPython: 8.14.0
  rioxarray: 0.14.1
  ghostscript: 10.02.1
GMT library information:
  binary version: 6.5.0
  cores: 4
  grid layout: rows
  image layout: 
  library path: /home/mkononets/mambaforge/envs/pygmt/lib/libgmt.so
  padding: 2
  plugin dir: /home/mkononets/mambaforge/envs/pygmt/lib/gmt/plugins
  share dir: /home/mkononets/mambaforge/envs/pygmt/share/gmt
  version: 6.5.0