René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Convert TransferFunction's shallow copy to deep copy.","articleBody":"I spent quite a bit of time trying to debug an error and finally stumbled on the documentation:\r\n\r\n    # Beware: this is a shallow copy! This should be okay,\r\n    # but be careful.\r\n\r\nIt took me a bit of digging and debugging before I realized my errors caused by the shallow copy:\r\n\r\n    \u003e\u003e\u003e print(num)\r\n    \u003e\u003e\u003e print(type(num[0]))\r\n\r\n    [[1], [2]]\r\n    \u003cclass 'list'\u003e\r\n\r\n    \u003e\u003e\u003e sys1 = control.TransferFunction([num],[den])\r\n    \u003e\u003e\u003e sys1\r\n\r\n    \u003e\u003e\u003e print(num)\r\n    \u003e\u003e\u003e print(type(num[0]))\r\n\r\n    [array([1]), array([2])]\r\n    \u003cclass 'numpy.ndarray'\u003e\r\n\r\nThis can make scripts behave different based on the order of operation:\r\n\r\n    num = ...\r\n    den = ...\r\n    myfunc(num)\r\n    TransferFunction(num, den)\r\n\r\nvs.\r\n\r\n    num = ...\r\n    den = ...\r\n    TransferFunction(num, den)\r\n    myfunc(num)\r\n\r\nTo new Python users having the variables 'num' \u0026 'den' behave different before and after calling ``TransferFunction`` can be confusing and off-putting. ","author":{"url":"https://github.com/dapperfu","@type":"Person","name":"dapperfu"},"datePublished":"2017-02-09T16:54:38.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":2},"url":"https://github.com/130/python-control/issues/130"}