code: def norm(vec):
      """Compute the (standard l2) norm of a vector.
  
      Parameters
      ----------
      vec: array of shape (dim,)
  
      Returns
      -------
      The l2 norm of vec.
      """
      result = 0.0
      for i in range(vec.shape[0]):
          result += vec[i] ** 2
      return np.sqrt(result)
  
file_path: umap/umap/utils.py
imports: import time
  from warnings import warn
  import numpy
  import numba
  from sklearn.utils.validation import check_is_fitted
  import scipy.sparse
label_desc: Use image node_id 4 for calling a global function with example usage: norm(vec) and returns: np