prasanjitdash
commented
3 years ago instead of using
img_data.plot.imshow(rgb='bands', vmin=0, vmax=1)I'd like to use cartopy+matplotlib as follows:
cs = ax.imshow(img_data, transform=data_crs, vmin=0, vmax=1, zorder=2)
Hi @djhoese
I think you can ignore the single question that I had. It seems like I can use CartoPy to plot a composite image. The single-band image was easy enough, but plotting the composite took me a while to understand. But if you know of a better way, I'd be glad to hear.
composite = 'true_color_lowres'
new_scn is the resampled scene object.
extent is the desired extent in [x0, x1, y0, y1]
%%time
with ProgressBar():
target_crs = ccrs.PlateCarree()
data_crs = new_scn[composite].attrs['area'].to_cartopy_crs()
fig, ax = plt.subplots(nrows=1,ncols=1, subplot_kw={'projection': target_crs}, \
figsize=({insert fig size})
ax.set_extent(extent)
ax.add_feature(land, linewidth=1., linestyle='--', alpha=1, zorder=0);
ax.add_feature(ocean, linewidth=1., linestyle='--', alpha=1, zorder=1);
# cs = ax.imshow(img, transform=data_crs, vmin=0, vmax=1, zorder=2)
img_data.plot.imshow(transform=data_crs, vmin=0, vmax=1, rgb='bands', zorder=2)
gl = ax.gridlines(crs=target_crs, draw_labels=True, linewidth=0.5, color='gray', alpha=0.8, linestyle='--')
gl.xformatter, gl.yformatter = LONGITUDE_FORMATTER, LATITUDE_FORMATTER
ax.add_feature(coastline, linewidth=1., linestyle='--', alpha=1, zorder=3);
plt.title(title, fontsize=18);
djhoese
My set-up specs: Windows 10, 32 Gb RAM, 6 cores (12 logical), Python 3.8
Feedback/minor hiccups
dask.persistthrows tuple out of index error but commenting it out allowed to run the script successfully. https://github.com/pytroll/tutorial-satpy-half-day/blob/644a0b9419c628c00f66a94064d7cb70f11b10d6/notebooks/04_resampling.ipynb#L504dynamic=Truecreated some issues (beyond my understanding!), but setting dynamic=False let it run. https://github.com/pytroll/tutorial-satpy-half-day/blob/644a0b9419c628c00f66a94064d7cb70f11b10d6/notebooks/07_cartopy_geoviews.ipynb#L246Please take a look when possible. These are minor issues.
Question (critical) I have a question related to the plotting of a given composite using
imshowrather than usingxarray.plot. The[bands, row, col]order in the dask/xarray seems like an issue forimshowand needs to be in image order[row, col, bands].For example, in the line: https://github.com/pytroll/tutorial-satpy-half-day/blob/644a0b9419c628c00f66a94064d7cb70f11b10d6/notebooks/05_composites.ipynb#L125
instead of using
img_data.plot.imshow(rgb='bands', vmin=0, vmax=1)I'd like to use cartopy+matplotlib as follows:
cs = ax.imshow(img_data, transform=data_crs, vmin=0, vmax=1, zorder=2)The img_data is a dask/xarray_core_array in [bands, row, col] order, e.g., (3 10000 10000). How to change it to image order [row, col, bands] e.g., (10000 10000 3)?
Overall, this is a terrific tool and very well implemented. Thank you, Prasanjit