code: def get_area_definition(pdict, a_ext):
      """Get the area definition for a geo-sat.
  
      Args:
          pdict: A dictionary containing common parameters:
              nlines: Number of lines in image
              ncols: Number of columns in image
              ssp_lon: Subsatellite point longitude (deg)
              a: Earth equatorial radius (m)
              b: Earth polar radius (m)
              h: Platform height (m)
              a_name: Area name
              a_desc: Area description
              p_id: Projection id
          a_ext: A four element tuple containing the area extent (scan angle)
                 for the scene in radians
      Returns:
          a_def: An area definition for the scene
  
      .. note::
  
          The AreaDefinition `proj_id` attribute is being deprecated.
  
      """
      proj_dict = {
          "a": float(pdict["a"]),
          "b": float(pdict["b"]),
          "lon_0": float(pdict["ssp_lon"]),
          "h": float(pdict["h"]),
          "proj": "geos",
          "units": "m",
      }
  
      a_def = geometry.AreaDefinition(
          pdict["a_name"],
          pdict["a_desc"],
          pdict["p_id"],
          proj_dict,
          int(pdict["ncols"]),
          int(pdict["nlines"]),
          a_ext,
      )
  
      return a_def
  
file_path: satpy/satpy/readers/_geos_area.py
imports: import numpy
  from pyresample import geometry
label_desc: Use image node_id 4 for calling a global function with example usage: get_area_definition(pdict, a_ext) and returns: a_def