#!/usr/bin/env python
# coding: utf-8

# ### Demonstrate new capability in Holoviz 1.14.0 to make missing data transparent when rasterizing integer data

# In[1]:


import xarray as xr
import hvplot.xarray
import holoviews; print(holoviews.__version__)


# In[2]:


url = 'https://landsat-pds.s3.amazonaws.com/c1/L8/047/027/LC08_L1TP_047027_20190406_20190422_01_T1/LC08_L1TP_047027_20190406_20190422_01_T1_B2.TIF'


# In[3]:


da = xr.open_rasterio(url).squeeze(dim='band')


# In[4]:


print(da)


# In[5]:


da.attrs['nodatavals'] = 0
da.attrs['missing_value'] = 0
da.attrs['_FillValue'] = 0
da.attrs['NODATA'] = 0


# In[6]:


print(da)


# In[ ]:





# By default `rasterize` renders the missing value 0 in this `uint16` data here:

# In[7]:


da.hvplot.image(x='x', y='y', crs='epsg:32610', tiles='OSM',
                rasterize=True, frame_width=300)


# We can now specify a `nodata` value to avoid this.  See Holoviews [Working with Large Data](https://holoviews.org/user_guide/Large_Data.html)

# In[8]:


da.hvplot.image(x='x', y='y', crs='epsg:32610', tiles='OSM',
                rasterize=True, frame_width=300).redim.nodata(value=0)