Error with yaml files during tutorial need example file I think

[hal98x]

Describe the bug
I went through the tutorial and ran into a few issues. I need an example yaml file for the my_rgb definitition somehow i wasn't able to recreate the syntax.

To Reproduce

sensor_name: visir/abi
composites:
  my_rgb:
    compositor: !!python/name:satpy.composites.GenericCompositor
    prerequisites:
    - r_band: C02
    - g_band: C11
    - b_band: C16

   enhancements:
     my_rgb:
       name: my_rgb
       operations:
       - name: color_limits
         method: !!python/name:satpy.enhancements.stretch
         kwargs: {stretch: 'crude', min_stretch: [RMIN, GMIN, BMIN], max_stretch: [RMAX, GMAX, BMAX]}

Expected behavior
I am getting error trying to load my_rgb

Actual results

ValueError                                Traceback (most recent call last)
<ipython-input-20-ef2a40ea4d11> in <module>
----> 1 new_scn = scn.resample(resampler='native')
      2 new_scn['my_rgb']

~\anaconda3\envs\satpy\lib\site-packages\satpy\scene.py in resample(self, destination, datasets, generate, unload, resampler, reduce_data, **resample_kwargs)
   1107 
   1108         if destination is None:
-> 1109             destination = self.max_area(to_resample_ids)
   1110         new_scn = self.copy(datasets=to_resample_ids)
   1111         # we may have some datasets we asked for but don't exist yet

~\anaconda3\envs\satpy\lib\site-packages\satpy\scene.py in max_area(self, datasets)
    270 
    271         """
--> 272         return self._compare_areas(datasets=datasets, compare_func=max)
    273 
    274     def min_area(self, datasets=None):

~\anaconda3\envs\satpy\lib\site-packages\satpy\scene.py in _compare_areas(self, datasets, compare_func)
    240         areas = [x for x in areas if x is not None]
    241         if not areas:
--> 242             raise ValueError("No dataset areas available")
    243 
    244         if not all(isinstance(x, type(areas[0]))

ValueError: No dataset areas available

Screenshots
If applicable, add screenshots to help explain your problem.

Environment Info:

• windows
• Satpy Version: current just downloaded and installed from conda forge
• PyResample Version:
• Readers and writers dependencies (when relevant): [run from satpy.config import check_satpy; check_satpy()]
  Could not import reader config from: ['C:\Users\paperspace\anaconda3\envs\satpy\Lib\site-packages\satpy\etc\readers\avhrr_l1b_gaclac.yaml']
  Could not import reader config from: ['C:\Users\paperspace\anaconda3\envs\satpy\Lib\site-packages\satpy\etc\readers\modis_l1b.yaml']
  Could not import reader config from: ['C:\Users\paperspace\anaconda3\envs\satpy\Lib\site-packages\satpy\etc\readers\caliop_l2_cloud.yaml']
  Could not import reader config from: ['C:\Users\paperspace\anaconda3\envs\satpy\Lib\site-packages\satpy\etc\readers\clavrx.yaml']
  Could not import reader config from: ['C:\Users\paperspace\anaconda3\envs\satpy\Lib\site-packages\satpy\etc\readers\modis_l2.yaml']
  Could not import reader config from: ['C:\Users\paperspace\anaconda3\envs\satpy\Lib\site-packages\satpy\etc\readers\iasi_l2_so2_bufr.yaml']
  Could not import reader config from: ['C:\Users\paperspace\anaconda3\envs\satpy\Lib\site-packages\satpy\etc\readers\viirs_edr_flood.yaml']
  Could not import reader config from: ['C:\Users\paperspace\anaconda3\envs\satpy\Lib\site-packages\satpy\etc\readers\seviri_l2_grib.yaml']
  Could not import reader config from: ['C:\Users\paperspace\anaconda3\envs\satpy\Lib\site-packages\satpy\etc\readers\li_l2.yaml']
  Could not import reader config from: ['C:\Users\paperspace\anaconda3\envs\satpy\Lib\site-packages\satpy\etc\readers\avhrr_l1b_hrpt.yaml']
  Could not import reader config from: ['C:\Users\paperspace\anaconda3\envs\satpy\Lib\site-packages\satpy\etc\readers\seviri_l1b_icare.yaml']
  Could not import reader config from: ['C:\Users\paperspace\anaconda3\envs\satpy\Lib\site-packages\satpy\etc\readers\hsaf_grib.yaml']
  Could not import reader config from: ['C:\Users\paperspace\anaconda3\envs\satpy\Lib\site-packages\satpy\etc\readers\grib.yaml']
  Could not import reader config from: ['C:\Users\paperspace\anaconda3\envs\satpy\Lib\site-packages\satpy\etc\readers\msi_safe.yaml']
  Could not import reader config from: ['C:\Users\paperspace\anaconda3\envs\satpy\Lib\site-packages\satpy\etc\readers\seviri_l2_bufr.yaml']
  Readers
  =======
  abi_l1b: ok
  abi_l1b_scmi: ok
  abi_l2_nc: ok
  acspo: ok
  agri_l1: ok
  ahi_hrit: ok
  ahi_hsd: ok
  ami_l1b: ok
  amsr2_l1b: ok
  amsr2_l2: ok
  avhrr_l1b_aapp: ok
  avhrr_l1b_eps: ok
  cmsaf-claas2_l2_nc: ok
  electrol_hrit: ok
  fci_l1c_fdhsi: ok
  fci_l2_nc: ok
  generic_image: ok
  geocat: ok
  ghrsst_l3c_sst: ok
  glm_l2: ok
  goes-imager_hrit: ok
  goes-imager_nc: ok
  gpm_imerg: ok
  hy2_scat_l2b_h5: ok
  iasi_l2: ok
  jami_hrit: ok
  maia: ok
  mersi2_l1b: ok
  mimicTPW2_comp: ok
  mtsat2-imager_hrit: ok
  nucaps: ok
  nwcsaf-geo: ok
  nwcsaf-msg2013-hdf5: ok
  nwcsaf-pps_nc: ok
  olci_l1b: ok
  olci_l2: ok
  omps_edr: ok
  safe_sar_l2_ocn: ok
  sar-c_safe: ok
  scatsat1_l2b: ok
  seviri_l1b_hrit: ok
  seviri_l1b_native: ok
  seviri_l1b_nc: ok
  slstr_l1b: ok
  slstr_l2: ok
  smos_l2_wind: ok
  tropomi_l2: ok
  vaisala_gld360: ok
  vii_l1b_nc: ok
  vii_l2_nc: ok
  viirs_compact: ok
  viirs_edr_active_fires: ok
  viirs_l1b: ok
  viirs_sdr: ok
  virr_l1b: ok

Writers

cf: ok
geotiff: ok
simple_image: ok

Extras

cartopy: ok
geoviews: ok

Additional context
Add any other context about the problem here.

[djhoese]

Interesting. Sorry you've had some trouble getting this to work. Based on the way you've pasted it, it seems you've added r_band: , g_band: , and b_band: to the prerequisite list. Was that added by you?

Edit: I see. The tutorial says name: . This is static text and is not something that the user needs to change. Sorry for the confusion.

[hal98x]

Yes I added r_band etc to the list The template in the tutorial was  - name : 'BANDID' I replaced name with name with my variable name but now that I think about it probable should put back  name? Sincerely, Michael Wallace On Monday, August 10, 2020, 06:04:04 AM MST, David Hoese <notifications@github.com> wrote: Interesting. Sorry you've had some trouble getting this to work. Based on the way you've pasted it, it seems you've added r_band: , g_band: , and b_band: to the prerequisite list. Was that added by you? — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub, or unsubscribe.

[djhoese]

The tutorial has:

composites:
  my_rgb:
    compositor: !!python/name:satpy.composites.GenericCompositor
    prerequisites:
    - name: YOUR_R_CHANNEL
    - name: YOUR_G_CHANNEL
    - name: YOUR_B_CHANNEL

You are meant to change the YOUR_X_CHANNEL portion of the text by replacing it with the name of the channel that we are using (ex. C01). I see now after rereading the text around it that I never explicitly showed what you are supposed to put in its place and most likely said this verbally when I presented this tutorial.

[hal98x]

Thanks for the very quick response and resolution. Hopefully this fixes the issue in the tutorial.  I was wondering if anyone had used SATPY in conjunction with ArcGIS API for python?  I was thinking about using Satpy Animation Tools to visualize changes over time, but I would first need to get the imagery data out of the feature service and into an array. Sincerely, Michael Wallace On Monday, August 10, 2020, 09:07:49 AM MST, David Hoese <notifications@github.com> wrote: The tutorial has: composites: my_rgb: compositor: !!python/name:satpy.composites.GenericCompositor prerequisites: - name: YOUR_R_CHANNEL - name: YOUR_G_CHANNEL - name: YOUR_B_CHANNEL You are meant to change the YOUR_X_CHANNEL portion of the text by replacing it with the name of the channel that we are using. I see now after rereading the text around it that I never explicitly showed what you are supposed to put in its place and most likely said this verbally when I presented this tutorial. — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub, or unsubscribe.

[djhoese]

I was wondering if anyone had used SATPY in conjunction with ArcGIS API for python?

Not that I'm aware.

[djhoese]

Closing as it sounds like the original issue has been fixed.