# Are there Sparse DAE Solvers available to simulate large models?

**URL:** <https://community.wolfram.com/t/are-there-sparse-dae-solvers-available-to-simulate-large-models/10544>\
**Category:** Questions\
**Tags:** modeling, system-modeler\
**Created:** [May 17, 2017, 11:16am UTC](https://community.wolfram.com/t/are-there-sparse-dae-solvers-available-to-simulate-large-models/10544 "2017-05-17T11:16:02Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![gwr](https://yyz1.discourse-cdn.com/wolfram/user_avatar/community.wolfram.com/gwr/32/34635_2.png) [@gwr](https://community.wolfram.com/u/gwr)\
**Post date:** [May 17, 2017, 11:16am UTC](https://community.wolfram.com/t/are-there-sparse-dae-solvers-available-to-simulate-large-models/10544/1 "2017-05-17T11:16:02Z")

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I recently became aware of this [paper](http://www.ep.liu.se/ecp/118/049/ecp15118459.pdf) by Francesco Casella regarding _“Simulation of Large-Scale Models in Modelica: State of the Art and Future Perspectives”_ where the lack of _Sparse DAE Solvers_ to work with large Modelica models is addressed. Coming from the [System Dynamics](https://en.wikipedia.org/wiki/System_dynamics) - Community, which makes use of ODE/DAE-Modeling in the social sciences and business, I noted that this very feature has been recently implemented by Ventana, a specialized software firm for SD-tools, in their new release of [_Ventity_](http://ventity.biz/), an object-oriented simulation tool, that allows sparse structures and dynamic generation of objects/entities.

**So the question is: Are there sparse DAE solvers available to simulate SystemModeler-models - especially using Mathematica to do simulation and analysis?**

While this is related to an earlier question I posted regarding [variable-structure systems](https://wolfram.discourse.group/t/6712/1) , I would like to make this a separate, concise question.

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**Author:** ![neils](https://yyz1.discourse-cdn.com/wolfram/user_avatar/community.wolfram.com/neils/32/20595_2.png) [@neils](https://community.wolfram.com/u/neils)\
**Post date:** [May 18, 2017, 6:11am UTC](https://community.wolfram.com/t/are-there-sparse-dae-solvers-available-to-simulate-large-models/10544/2 "2017-05-18T06:11:45Z")

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Guido,

WSM supports the CVODES solver. CVODES is a sparse DAE solver. I do not know if WSM uses the sparse features in CVODES – the developers would have to answer that question.

Regards

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**Author:** ![henrikt](https://yyz1.discourse-cdn.com/wolfram/user_avatar/community.wolfram.com/henrikt/32/24544_2.png) [@henrikt](https://community.wolfram.com/u/henrikt)\
**Post date:** [May 18, 2017, 8:07am UTC](https://community.wolfram.com/t/are-there-sparse-dae-solvers-available-to-simulate-large-models/10544/3 "2017-05-18T08:07:54Z")

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Sparsity is utilized in in several ways by SystemModeler. First, the symbolic processing applies standard techniques such as transformation into block lower triangular form and tearing. Then, sparsity of linear equation systems at runtime are handled using techniques for sparse linear algebra.