code: def get_parser():
      parser = argparse.ArgumentParser(
          description="compute a pca matrix given an array of numpy features"
      )
      parser.add_argument("data", help="features scp files")
      parser.add_argument(
          "--output", help="where to save the pca matrix", required=True
      )
      parser.add_argument(
          "--dim", type=int, help="dim for pca reduction", required=True
      )
      parser.add_argument(
          "--eigen_power",
          type=float,
          default=0,
          help="eigen power, -0.5 for whitening",
      )
  
      return parser
  
imports: import argparse
  import os
  import os.path
  import faiss
  import numpy
label_desc: Use image node_id 1 for calling a global function with example usage: get_parser() and returns: parser