code: def time_dist(dtime_amin_s, dtime_amin_t):
      dt = dtime_amin_t - dtime_amin_s
      return dt
  
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 8 for calling a global function with example usage: time_dist(dtime_amin_s, dtime_amin_t) and returns: dt