code: def waveform_length(X):
      """cumulative length of the waveform over a segment for each variable in the segmented time
      series"""
      return np.sum(np.abs(np.diff(X, axis=1)), axis=1)
  
imports: import numpy
  from scipy import stats
label_desc: Use image node_id 26 for calling a global function with example usage: waveform_length(X) and returns: np