code: def _compute_derivative_from_values(values, values_plus_dt, dt=0.1):
      """Return the time or dispersion derivative of an hrf."""
      return 1.0 / dt * (values - values_plus_dt)
  
imports: import warnings
  from collections.abc import Iterable
  import numpy
  from scipy.stats import gamma
  from nilearn._utils import fill_doc
label_desc: Use image node_id 4 for calling a global function with example usage: _compute_derivative_from_values(values, values_plus_dt, dt) and returns: unknown