code: def bucketize(matrix):
      row_indices = matrix.indices()[0]
      arange = torch.arange(
          matrix.size(0) + 1, device=row_indices.device
      )
      return torch.bucketize(arange, row_indices)
  
file_path: pytorch_sparse/benchmark/ptr2ind.py
imports: import os
  import wget
  import time
  import errno
  import argparse
  import os.path
  import torch
  from scipy.io import loadmat
label_desc: Use image node_id 3 for calling a global function with example usage: bucketize(matrix) and returns: torch