René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Implement a better algorithm for pole placement","articleBody":"Hello!\nI've happened to compare pole placement with Matlab's, and found out that returned matrix doesn't make the poles fall in the chosen values.\nI made an example script just like `python-control/examples/slicot-test.py` for matlab and python.\n\nMatlab script:\n\n```\nA = [\n[                0, 0, 0, 1],\n[-42.7207306947135, 0, 0, 0],\n[                0, 0, 0, 0],\n[ 47.0334901743703, 0, 0, 0]];\n\nC = [[ 1.,  0.,  0.,  0.],\n       [ 0.,  1.,  0.,  0.],\n       [ 0.,  0.,  1.,  0.],\n       [ 0.,  0.,  0.,  1.]];\n\np = [-31., -21., -20., -30.];\n\nL = place(A',C',p)\neigs(A' - C'*L)\n\n% L= 31.0000  -42.7207         0   47.0335\n%          0   21.0000         0         0\n%          0         0   20.0000         0\n%     1.0000         0         0   30.0000\n% eigs = -20, -21, -30, -31\n```\n\nPython script:\n\n```\nimport numpy as np              # Numerical library\nfrom scipy import *             # Load the scipy functions\nfrom control.matlab import *    # Load the controls systems library\n\nA = matrix([\n[                0, 0, 0, 1],\n[-42.7207306947135, 0, 0, 0],\n[                0, 0, 0, 0],\n[ 47.0334901743703, 0, 0, 0]])\n\nC = matrix([[ 1.,  0.,  0.,  0.],\n       [ 0.,  1.,  0.,  0.],\n       [ 0.,  0.,  1.,  0.],\n       [ 0.,  0.,  0.,  1.]])\n\np = [-31., -21., -20., -30.]\nL = place(A.T, C.T, p)\nprint \"Pole place: L = \", L\nprint \"Pole place: eigs = \", np.linalg.eig(A.T - C.T * L)[0]\n\n#Pole place: L =  [[  0.73152698  -1.12180554  -0.           5.01688279]\n# [ -1.12180554  22.72030247  -0.          -7.69345088]\n# [ -0.          -0.          20.          -0.        ]\n# [  5.01688279  -7.69345088  -0.          34.40626723]]\n#Pole place: eigs =  [ -6.85809669 -30.         -21.         -20.        ]\n# \u003e\u003e\u003e control.__version__\n# '0.7.0'\n```\n\nAm I using it wrong?\n","author":{"url":"https://github.com/vmatos","@type":"Person","name":"vmatos"},"datePublished":"2016-10-11T14:44:51.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":5},"url":"https://github.com/117/python-control/issues/117"}