id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
4034	Use sparse solvers for event handling in daemode	Francesco Casella	Andreas Heuermann	"The simulation time for models with many when clauses and large implicit systems of equations, which is one class of models where using daemode makes lots of sense, scales as O(N^3^). See, e.g., the {{{BreakerNetwork}}} and {{{BreakerNetworkDelayed}}} models in the ScalableTestSuite https://test.openmodelica.org/libraries/ScalableTestSuite_Experimental/BuildModelRecursive.html

As far as I understand, this is due to the fact that, during event handling, the dynamic equations and the equations of the active when clauses are solved using a dense solver, whose solution time is cubic with the size. 

If the equations are linear, the {{{-lssMaxDensity}}} and {{{-lssMinSize}}} values should be used to automatically trigger the use of a sparse solver also in this case. I understand this should be enough to handle the ScalableTestSuite test cases efficiently.

The sparse Kinsol solver should be implemented instead, in order to handle the models with large nonlinear implicit equation systems."	enhancement	closed	high	1.19.0	Run-time		fixed