René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"miso tf2ss fails without slycot","articleBody":"This looks like it is failing to throw the warning to the user about it being miso and not supported without slycot for some reason.\r\n\r\n```bash\r\ntf = control.tf([[[-235, 1.146e4],\r\n    [-235, 1.146E4],\r\n    [-235, 1.146E4, 0]]],\r\n    [[[1, 48.78, 0],\r\n      [1, 48.78, 0, 0],\r\n      [0.008, 1.39, 48.78]]])\r\ntf\r\nOut[80]:\r\n\r\nInput 1 to output 1:\r\n-235 s + 1.146e+04\r\n------------------\r\n  s^2 + 48.78 s\r\n\r\nInput 2 to output 1:\r\n-235 s + 1.146e+04\r\n------------------\r\n  s^3 + 48.78 s^2\r\n\r\nInput 3 to output 1:\r\n  -235 s^2 + 1.146e+04 s\r\n--------------------------\r\n0.008 s^2 + 1.39 s + 48.78\r\nIn [81]:\r\n\r\n​\r\ncontrol.tf2ss(tf)\r\n---------------------------------------------------------------------------\r\nImportError                               Traceback (most recent call last)\r\n/home/jgoppert/anaconda3/lib/python3.5/site-packages/control-dev-py3.5.egg/control/statesp.py in _convertToStateSpace(sys, **kw)\r\n    646         try:\r\n--\u003e 647             from slycot import td04ad\r\n    648             if len(kw):\r\n\r\nImportError: No module named 'slycot'\r\n\r\nDuring handling of the above exception, another exception occurred:\r\n\r\nValueError                                Traceback (most recent call last)\r\n\u003cipython-input-81-c8ef26438f31\u003e in \u003cmodule\u003e()\r\n      1 \r\n----\u003e 2 control.tf2ss(tf)\r\n\r\n/home/jgoppert/anaconda3/lib/python3.5/site-packages/control-dev-py3.5.egg/control/statesp.py in tf2ss(*args)\r\n   1082             raise TypeError(\"tf2ss(sys): sys must be a TransferFunction \\\r\n   1083 object.\")\r\n-\u003e 1084         return _convertToStateSpace(sys)\r\n   1085     else:\r\n   1086         raise ValueError(\"Needs 1 or 2 arguments; received %i.\" % len(args))\r\n\r\n/home/jgoppert/anaconda3/lib/python3.5/site-packages/control-dev-py3.5.egg/control/statesp.py in _convertToStateSpace(sys, **kw)\r\n    671             # I think this will fail if num and den aren't 1-D after\r\n    672             # the squeeze\r\n--\u003e 673             lti_sys = lti(squeeze(sys.num), squeeze(sys.den))\r\n    674             return StateSpace(lti_sys.A, lti_sys.B, lti_sys.C, lti_sys.D,\r\n    675                               sys.dt)\r\n\r\n/home/jgoppert/anaconda3/lib/python3.5/site-packages/scipy/signal/ltisys.py in __init__(self, *system, **kwargs)\r\n    759         self._den = None\r\n    760 \r\n--\u003e 761         self.num, self.den = normalize(*system)\r\n    762 \r\n    763     def __repr__(self):\r\n\r\n/home/jgoppert/anaconda3/lib/python3.5/site-packages/scipy/signal/filter_design.py in normalize(b, a)\r\n   1084     if len(b.shape) == 1:\r\n   1085         b = asarray([b], b.dtype.char)\r\n-\u003e 1086     while a[0] == 0.0 and len(a) \u003e 1:\r\n   1087         a = a[1:]\r\n   1088     outb = b * (1.0) / a[0]\r\n\r\nValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()\r\n```","author":{"url":"https://github.com/jgoppert","@type":"Person","name":"jgoppert"},"datePublished":"2016-11-14T05:14:09.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":3},"url":"https://github.com/120/python-control/issues/120"}