Updating attributes with band math about geowombat HOT 5 CLOSED

The band math attributes below will now be updated.

new_attrs['nodatavals'] = (nodata)
new_attrs['scales'] = (1.0)
new_attrs['offsets'] = (0.0)

I also added a 'vi' attribute. When I merge your examples I will push these changes with version 1.2.5.

from geowombat.

Maybe I should show the exact issue I am seeing, maybe not related to attributes.

with gw.config.update(sensor='rgbn', scale_factor=0.0001):
    with gw.open([rgbn_suba, rgbn_subb],
          band_names=['blue', 'green', 'red', 'nir'],
          mosaic=True,
          bounds_by='union') as ds_mos:
                
                ndvi = ds_mos.gw.ndvi()

                # Xarray drops attributes
                attrs = ndvi.attrs.copy()
                ndvi.attrs['nodatavals'] = (0.0)
                ndvi.attrs['scales'] = (1.0)
                ndvi.attrs['offsets'] = (0.0)
 
                ndvi.attrs = attrs
                print(attrs)
                # Write the data to a GeoTiff
                ndvi.gw.to_raster( '/home/mmann1123/Desktop/output2.tif',
                                    verbose=1,
                                    n_workers=4,    # number of process workers sent to ``concurrent.futures``
                                    n_threads=2,    # number of thread workers sent to ``dask.compute``
                                    n_chunks=200)   # number of window chunks

throws:

ValueError: Source shape (1, 64) is inconsistent with given indexes 1

I am assuming it has to do with the use of the config, but not sure there is a config for single band...

from geowombat.

I agree, the attributes should be updated for band math.

I will see if I can figure out the shape issue. One quick note--if you specify the sensor in the configuration then you don't have to specify the band names in gw.open(). But, I see that I named the files incorrectly. They are stored as blue, green, red, NIR, not red, gree, blue, NIR.

from geowombat.

Ok, the attributes were not the issue when writing the results to file. The problem seems to be the chunk size. The image block size is 64x64, which led to a single row/column at the image edge. Using a larger chunk size fixed it.

>>> with gw.config.update(sensor='bgrn', scale_factor=0.0001):
>>>     
>>>     with gw.open([rgbn_suba, rgbn_subb],
>>>                  mosaic=True,
>>>                  bounds_by='union',
>>>                  chunks=256) as ds_mos:
>>> 
>>>         attrs = ds_mos.attrs.copy()
>>>         
>>>         # Calculate the NDVI
>>>         ndvi = ds_mos.gw.ndvi()
>>>         
>>>         # Mask the NDVI
>>>         masker = ndvi >= -0.25
>>>         ndvi = ndvi * masker
>>>         
>>>         # The 'no data' values are set as None from `ds_mos.gw.ndvi()`
>>>         # After masking, set the 'no data' values as 0.
>>>         ndvi.attrs = attrs
>>>         ndvi.attrs['nodatavals'] = (0)
>>>         
>>>         # Write the data to a GeoTiff
>>>         ndvi.gw.to_raster('ndvi.tif',
>>>                           overwrite=True,
>>>                           n_workers=4,    # number of process workers sent to ``concurrent.futures``
>>>                           n_threads=2,    # number of thread workers sent to ``dask.compute``
>>>                           n_chunks=200,   # number of window chunks
>>>                           compress='lzw')

from geowombat.

I am closing this for now, but we can reopen if there are additional attributes that we want to add.

from geowombat.