code: def glover_hrf(tr, oversampling=16, time_length=32.0, onset=0.0):
      """Implementation of the Glover hrf model
  
      Parameters
      ----------
      tr: float, scan repeat time, in seconds
      oversampling: int, temporal oversampling factor, optional
      time_length: float, hrf kernel length, in seconds
      onset: float, onset of the response
  
      Returns
      -------
      hrf: array of shape(length / tr * oversampling, float),
           hrf sampling on the oversampled time grid
      """
      return _gamma_difference_hrf(
          tr,
          oversampling,
          time_length,
          onset,
          delay=6,
          undershoot=12.0,
          dispersion=0.9,
          u_dispersion=0.9,
          ratio=0.35,
      )
  
file_path: nipy/nipy/modalities/fmri/hemodynamic_models.py
imports: import warnings
  import numpy
  from scipy.stats import gamma
label_desc: Use image node_id 3 for calling a global function with example usage: glover_hrf(tr, oversampling, time_length, onset) and returns: _gamma_difference_hrf