{"action":"created","issue":{"url":"https://api.github.com/repos/tbeu/Modelica/issues/1509","repository_url":"https://api.github.com/repos/tbeu/Modelica","labels_url":"https://api.github.com/repos/tbeu/Modelica/issues/1509/labels{/name}","comments_url":"https://api.github.com/repos/tbeu/Modelica/issues/1509/comments","events_url":"https://api.github.com/repos/tbeu/Modelica/issues/1509/events","html_url":"https://github.com/tbeu/Modelica/issues/1509","id":200249541,"number":1509,"title":"Guess value for thermodynamicstate.X","user":{"login":"modelica-trac-importer","id":22202507,"avatar_url":"https://avatars.githubusercontent.com/u/22202507?v=3","gravatar_id":"","url":"https://api.github.com/users/modelica-trac-importer","html_url":"https://github.com/modelica-trac-importer","followers_url":"https://api.github.com/users/modelica-trac-importer/followers","following_url":"https://api.github.com/users/modelica-trac-importer/following{/other_user}","gists_url":"https://api.github.com/users/modelica-trac-importer/gists{/gist_id}","starred_url":"https://api.github.com/users/modelica-trac-importer/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/modelica-trac-importer/subscriptions","organizations_url":"https://api.github.com/users/modelica-trac-importer/orgs","repos_url":"https://api.github.com/users/modelica-trac-importer/repos","events_url":"https://api.github.com/users/modelica-trac-importer/events{/privacy}","received_events_url":"https://api.github.com/users/modelica-trac-importer/received_events","type":"User","site_admin":false},"labels":[{"id":515527756,"url":"https://api.github.com/repos/tbeu/Modelica/labels/enhancement","name":"enhancement","color":"84b6eb","default":true},{"id":515539297,"url":"https://api.github.com/repos/tbeu/Modelica/labels/L:%20Media","name":"L: Media","color":"0000aa","default":false}],"state":"closed","locked":false,"assignee":{"login":"beutlich","id":14896695,"avatar_url":"https://avatars.githubusercontent.com/u/14896695?v=3","gravatar_id":"","url":"https://api.github.com/users/beutlich","html_url":"https://github.com/beutlich","followers_url":"https://api.github.com/users/beutlich/followers","following_url":"https://api.github.com/users/beutlich/following{/other_user}","gists_url":"https://api.github.com/users/beutlich/gists{/gist_id}","starred_url":"https://api.github.com/users/beutlich/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/beutlich/subscriptions","organizations_url":"https://api.github.com/users/beutlich/orgs","repos_url":"https://api.github.com/users/beutlich/repos","events_url":"https://api.github.com/users/beutlich/events{/privacy}","received_events_url":"https://api.github.com/users/beutlich/received_events","type":"User","site_admin":false},"assignees":[{"login":"beutlich","id":14896695,"avatar_url":"https://avatars.githubusercontent.com/u/14896695?v=3","gravatar_id":"","url":"https://api.github.com/users/beutlich","html_url":"https://github.com/beutlich","followers_url":"https://api.github.com/users/beutlich/followers","following_url":"https://api.github.com/users/beutlich/following{/other_user}","gists_url":"https://api.github.com/users/beutlich/gists{/gist_id}","starred_url":"https://api.github.com/users/beutlich/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/beutlich/subscriptions","organizations_url":"https://api.github.com/users/beutlich/orgs","repos_url":"https://api.github.com/users/beutlich/repos","events_url":"https://api.github.com/users/beutlich/events{/privacy}","received_events_url":"https://api.github.com/users/beutlich/received_events","type":"User","site_admin":false}],"milestone":{"url":"https://api.github.com/repos/tbeu/Modelica/milestones/59","html_url":"https://github.com/tbeu/Modelica/milestone/59","labels_url":"https://api.github.com/repos/tbeu/Modelica/milestones/59/labels","id":2241930,"number":59,"title":"MSL3.2.2","description":"","creator":{"login":"modelica-trac-importer","id":22202507,"avatar_url":"https://avatars.githubusercontent.com/u/22202507?v=3","gravatar_id":"","url":"https://api.github.com/users/modelica-trac-importer","html_url":"https://github.com/modelica-trac-importer","followers_url":"https://api.github.com/users/modelica-trac-importer/followers","following_url":"https://api.github.com/users/modelica-trac-importer/following{/other_user}","gists_url":"https://api.github.com/users/modelica-trac-importer/gists{/gist_id}","starred_url":"https://api.github.com/users/modelica-trac-importer/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/modelica-trac-importer/subscriptions","organizations_url":"https://api.github.com/users/modelica-trac-importer/orgs","repos_url":"https://api.github.com/users/modelica-trac-importer/repos","events_url":"https://api.github.com/users/modelica-trac-importer/events{/privacy}","received_events_url":"https://api.github.com/users/modelica-trac-importer/received_events","type":"User","site_admin":false},"open_issues":0,"closed_issues":39,"state":"closed","created_at":"2017-01-10T20:32:15Z","updated_at":"2017-01-12T00:47:04Z","due_on":"2016-03-11T08:00:00Z","closed_at":"2017-01-10T20:32:15Z"},"comments":5,"created_at":"2017-01-12T00:45:34Z","updated_at":"2017-01-12T00:47:14Z","closed_at":"2017-01-12T00:47:04Z","body":"**Reported by filip&#46;jorissen on 10 Jun 2014 16:55 UTC**\nI have a model where 'X[2]' of a moist air was chosen by Dymola as the iteration variable of a nonlinear system of equations. The default guess value is 0, which causes an error:\n\n```\nThe following error was detected at time: 0\n\nModel error - power: (r1) ** (n[1]) = (-3.83338) ** (-1.5)\n\nThe stack of functions is:\nBuildings.Media.PerfectGases.MoistAir.sublimationPressureIce\nBuildings.Media.PerfectGases.MoistAir.saturationPressure\nBuildings.Media.GasesPTDecoupled.MoistAir.T_phX\nBuildings.Media.GasesPTDecoupled.MoistAir.T_phX(menergaAdsolair.heating.state_a1_inflow.p, menergaAdsolair.filter.port_b.h_outflow, menergaAdsolair.filter.port_b.Xi_outflow)\nFirst evaluation failed for non-linear solver.\n\netc etc\n\nERROR: Failed to solve non-linear system using Newton solver.\nTo get more information: Turn on Simulation/Setup/Debug/Nonlinear solver diagnostics/Details\nSolution to systems of equations not found at time = 0\n   Nonlinear system of equations number = 15\n   Failed to evaluate any residual. Try to give better start-values.\n   Iteration is not making good progress.\n   Accumulated number of residue calculations: 4\n   Last values of solution vector:\nmenergaAdsolair.heating.state_a1_inflow.X[2] = 1E-09\nmenergaAdsolair.thermostatic3WayValve.k = 0.5\nmenergaAdsolair.filter.port_b.h_outflow = 45301\nError: could not solve simplified initialization for homotopy method.\nError: could not solve simplified initialization for homotopy method.\nError: Failed to start model.\n```\n\nI solved this by setting the initial guess value for ThermodynamicState.X equal to reference_X. I suggest to implement this by default in MSL and possibly also for p, T and h.\n\nThe hotfix for my own package was:\n```\nredeclare record extends ThermodynamicState(X(start=reference_X)) \n  \"ThermodynamicState record for moist air\"\nend ThermodynamicState;\n```\n\n\n----\n\nMigrated-From: https://trac.modelica.org/Modelica/ticket/1509"},"comment":{"url":"https://api.github.com/repos/tbeu/Modelica/issues/comments/272042897","html_url":"https://github.com/tbeu/Modelica/issues/1509#issuecomment-272042897","issue_url":"https://api.github.com/repos/tbeu/Modelica/issues/1509","id":272042897,"user":{"login":"modelica-trac-importer","id":22202507,"avatar_url":"https://avatars.githubusercontent.com/u/22202507?v=3","gravatar_id":"","url":"https://api.github.com/users/modelica-trac-importer","html_url":"https://github.com/modelica-trac-importer","followers_url":"https://api.github.com/users/modelica-trac-importer/followers","following_url":"https://api.github.com/users/modelica-trac-importer/following{/other_user}","gists_url":"https://api.github.com/users/modelica-trac-importer/gists{/gist_id}","starred_url":"https://api.github.com/users/modelica-trac-importer/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/modelica-trac-importer/subscriptions","organizations_url":"https://api.github.com/users/modelica-trac-importer/orgs","repos_url":"https://api.github.com/users/modelica-trac-importer/repos","events_url":"https://api.github.com/users/modelica-trac-importer/events{/privacy}","received_events_url":"https://api.github.com/users/modelica-trac-importer/received_events","type":"User","site_admin":false},"created_at":"2017-01-12T00:47:14Z","updated_at":"2017-01-12T00:47:14Z","body":"**Modified by beutlich on 13 Dec 2015 08:26 UTC**"}}
{"actor":{"display_login":"modelica-trac-importer"}}