René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Regression: root-locus plots may be coarse, and no longer react to zoom events","articleBody":"Root-locus (and sisotool root-locus) used to recompute their points when zooming in on the root-locus plot (typically to get to the dominant pole group). At zoom-in, the new xlim and ylim are used to recompute the RL lines. \n\nCurrently root-locus does not recompute, and zoomed-in plots show (sometimes unusably) coarse edgy root-locuses. The recompute was removed in commit  \n\n    57dac87da3c5885ef4912fa4484a0dff811e0b9c    Initial refactoring of root_locus_{map,plot}\n\nI am currently trying to figure out how to bring recalculation of the plot back.\n\nExample:\n\n    import control.matlab as ml\n    from matplotlib import pyplot as plt\n\n    s = ml.tf('s')\n    H = (s+1)/s**2/(s**2+2*s+7)/(s+15)\n    ml.rlocus(H)\n    plt.show()\n\n![Image](https://github.com/user-attachments/assets/ea4b5848-174b-4d80-acdc-7e3f8bf47dfb)\n\n\n","author":{"url":"https://github.com/repagh","@type":"Person","name":"repagh"},"datePublished":"2025-06-04T13:37:02.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":2},"url":"https://github.com/1151/python-control/issues/1151"}