code: def normalize_data(batch_data):
      """Normalize the batch data, use coordinates of the block centered at origin,
      Input:
          BxNxC array
      Output:
          BxNxC array
      """
      B, N, C = batch_data.shape
      normal_data = np.zeros((B, N, C))
      for b in range(B):
          pc = batch_data[b]
          centroid = np.mean(pc, axis=0)
          pc = pc - centroid
          m = np.max(np.sqrt(np.sum(pc**2, axis=1)))
          pc = pc / m
          normal_data[b] = pc
      return normal_data
  
file_path: dgl/examples/pytorch/pointcloud/pointnet/provider.py
imports: import numpy
label_desc: Use image node_id 1 for calling a global function with example usage: normalize_data(batch_data) and returns: normal_data