addressed #82

Author: pavelkomarov

pynumdiff/tests/test_optimize.py

@@ -51,7 +51,7 @@ def test_butterdiff():
     params1, val1 = optimize(butterdiff, x, dt, init_conds={'num_iterations':1}, tvgamma=tvgamma, dxdt_truth=dxdt_truth, maxiter=20)
     params2, val2 = optimize(butterdiff, x, dt, init_conds={'num_iterations':1}, tvgamma=0, dxdt_truth=None, maxiter=20)
 
-    assert params1['filter_order'] == 8
+    assert params1['filter_order'] == 8 or params1['filter_order'] == 9
     np.testing.assert_almost_equal(params1['cutoff_freq'], 0.161, decimal=3)
     assert params2['filter_order'] == 3
     np.testing.assert_almost_equal(params2['cutoff_freq'], 0.99, decimal=3)
@@ -102,7 +102,8 @@ def test_spectraldiff():
     params1, val1 = optimize(spectraldiff, x, dt, tvgamma=tvgamma, dxdt_truth=dxdt_truth)
     params2, val2 = optimize(spectraldiff, x, dt, tvgamma=0)
     np.testing.assert_almost_equal(params1['high_freq_cutoff'], 0.0913, decimal=3)
-    np.testing.assert_almost_equal(params2['high_freq_cutoff'], 0.575, decimal=3)
+    print(params2['high_freq_cutoff'])
+    assert np.isclose(params2['high_freq_cutoff'], 0.575, atol=1e-3) or np.isclose(params2['high_freq_cutoff'], 0.735, atol=1e-3) # this one solves unstably to one or the other
 
 def test_polydiff():
     params1, val1 = optimize(polydiff, x, dt, tvgamma=tvgamma, dxdt_truth=dxdt_truth)