code: def count(cp):
      return len(set(cp[cp != 0]))
  
file_path: deepgraph/doc/source/tutorials/precipitation.py
imports: import os
  import xarray
  import matplotlib.pyplot
  import numpy
  import pandas
  import deepgraph
  from mpl_toolkits.basemap import Basemap
  from scipy.cluster.hierarchy import linkage, fcluster
label_desc: Use image node_id 9 for calling a global function with example usage: count(cp) and returns: len