IndexError in test_gradients about pymc HOT 2 CLOSED

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FAIL: test_gradients (pymc.tests.test_gradients.test_gradients)
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Traceback (most recent call last):
  File "/Users/fonnescj/Code/pymc/pymc/tests/test_gradients.py", line 291, in test_gradients
    check_gradients(gamma)
  File "/Users/fonnescj/Code/pymc/pymc/tests/test_gradients.py", line 112, in check_gradients
    " is not correct.")
  File "/Library/Python/2.7/site-packages/numpy-2.0.0.dev_730b861_20110815-py2.7-macosx-10.7-x86_64.egg/numpy/testing/utils.py", line 799, in assert_array_almost_equal
    header=('Arrays are not almost equal to %d decimals' % decimal))
  File "/Library/Python/2.7/site-packages/numpy-2.0.0.dev_730b861_20110815-py2.7-macosx-10.7-x86_64.egg/numpy/testing/utils.py", line 635, in assert_array_compare
    raise AssertionError(msg)
AssertionError: 
Arrays are not almost equal to 4 decimals
analytic gradient for gamma with respect to parameter a is not correct.
(mismatch 100.0%)
 x: array([-0.96673602, -1.41302081, -2.3154314 , -2.84824608, -1.73328374])
 y: array([-0.54395252, -0.99024297, -1.89264995, -2.42546566, -1.31050626])