René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Too few poles for MIMO tf","articleBody":"2x2 MIMO system I/s (diagonal, integrators on diagonal) is reported as having 1 pole.  Converting to state-space gives the correct number of poles.\n\ntested with slycot https://github.com/python-control/Slycot/commit/a1f43abe0efadd2f03115ea0c990544627205230 and python-control cdd3e73838cea0b26a7155d0b2084aa698e5eefd\n\n``` python\nimport numpy as np\nimport control\n\nnum = [ [ [1], [0] ],\n        [ [0], [1] ] ]\n\nden = [ [ [1,0], [1] ],\n        [ [1],   [1,0] ] ]\n\ng = control.tf(num,den)\nprint('g.pole()',g.pole())\nprint('control.ss(g).pole()',control.ss(g).pole())\n```\n\noutput:\n\n```\ng.pole() [ 0.]\ncontrol.ss(g).pole() [-0. -0.]\n```\n","author":{"url":"https://github.com/roryyorke","@type":"Person","name":"roryyorke"},"datePublished":"2016-09-08T18:32:34.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":10},"url":"https://github.com/111/python-control/issues/111"}