René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"step function","articleBody":"Hi there, seems like the step function code in the tutorial has some mistakes as it gives me the following error:\r\n\r\nModelException: Invalid control function for var: 0.\r\n Control functions should be of the form:\r\n0 = f(t, x, dx/dt)\r\n\r\n```\r\nfrom BondGraphTools import *\r\n\r\n#%%\r\n\r\nmodel = new(name= 'RC')\r\n\r\n#%%\r\nC = new(\"C\", value= 1)\r\nR = new(\"R\", value= 1)\r\nKCL = new(\"0\")\r\n\r\n#%%\r\n\r\nadd(model, R, C, KCL)\r\nconnect(R, KCL)\r\nconnect(KCL, C)\r\n\r\n#%%\r\n\r\nSf = new(\"Sf\")\r\nadd(model, Sf)\r\nconnect(Sf, KCL)\r\ndraw(model)\r\n\r\n\r\n#%%\r\ntimespan = [0, 5]\r\nx0 = {'x_0':1}\r\n\r\nstep_fn = {'u_0': 't \u003c 1 ? 1 : 0'} # if t \u003c 0 then 1 else 0\r\nt, x = simulate(model, timespan=timespan, x0=x0, control_vars= step_fn)\r\nplot(t,x)\r\n```\r\nThanks","author":{"url":"https://github.com/Niimaa","@type":"Person","name":"Niimaa"},"datePublished":"2021-07-26T22:16:41.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":0},"url":"https://github.com/2/BondGraphTools-Tutorials/issues/2"}