code: def chirp_geometric(t, f0, f1, t1):
      f = f0 * (f1 / f0) ** (t / t1)
      return f
  
imports: from __future__ import division, print_function, absolute_import
  import numpy
  from numpy.testing import assert_almost_equal, assert_equal, assert_, assert_allclose, assert_array_equal
  from pytest import raises
  import scipy.signal.waveforms
label_desc: Use image node_id 3 for calling a global function with example usage: chirp_geometric(t, f0, f1, t1) and returns: f