René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"xferfcn_test test_pole_mimo fails on arm and powerpc","articleBody":"As a continuation of my efforts to provide packages of python-control and slycot for OpenSUSE ( see python-control/Slycot#82 and python-control/Slycot#83), python-control now starts to build (because python-slycot is avaialble now) but fails on test_pole_mimo in xferfcn_test.py:\r\n\r\n```\r\n[  269s] ======================================================================\r\n[  269s] FAIL: Test for correct MIMO poles.\r\n[  269s] ----------------------------------------------------------------------\r\n[  269s] Traceback (most recent call last):\r\n[  269s]   File \"/home/abuild/rpmbuild/BUILD/control-0.8.2/control/tests/xferfcn_test.py\", line 415, in test_pole_mimo\r\n[  269s]     np.testing.assert_array_almost_equal(p, [-2., -2., -7., -3., -2.])\r\n[  269s]   File \"/usr/lib64/python2.7/site-packages/numpy/testing/_private/utils.py\", line 1017, in assert_array_almost_equal\r\n[  269s]     precision=decimal)\r\n[  269s]   File \"/usr/lib64/python2.7/site-packages/numpy/testing/_private/utils.py\", line 754, in assert_array_compare\r\n[  269s]     raise AssertionError(msg)\r\n[  269s] AssertionError: \r\n[  269s] Arrays are not almost equal to 6 decimals\r\n[  269s] \r\n[  269s] (shapes (6,), (5,) mismatch)\r\n[  269s]  x: array([-1.999985+0.000000e+00j, -2.000007+1.271532e-05j,\r\n[  269s]        -2.000007-1.271532e-05j, -7.      +0.000000e+00j,\r\n[  269s]        -3.      +0.000000e+00j, -2.      +0.000000e+00j])\r\n[  269s]  y: array([-2., -2., -7., -3., -2.])\r\n```\r\n\r\n`_common_den()` strikes again (#194, #206). I see it has the optional argument `imag_tol`, but it is never used within the function except where it is set to 1e-8 by default.\r\n\r\nAny ideas how to fix this? Is the resulting machine precision on theses arches really worse than the x86 build, where this tests fine? Or is there maybe a problem with the slycot / lapack / (open)blas / numpy environment on those build machines?","author":{"url":"https://github.com/bnavigator","@type":"Person","name":"bnavigator"},"datePublished":"2019-11-09T13:25:24.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":6},"url":"https://github.com/343/python-control/issues/343"}