# Convergence plot

**URL:** <https://festim.discourse.group/t/convergence-plot/23>\
**Category:** User Support\
**Created:** [December 14, 2023, 4:08pm UTC](https://festim.discourse.group/t/convergence-plot/23 "2023-12-14T16:08:54Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![VVKulagin](https://yyz2.discourse-cdn.com/free1/user_avatar/festim.discourse.group/vvkulagin/32/51_2.png) [@VVKulagin](https://festim.discourse.group/u/VVKulagin)\
**Post date:** [December 14, 2023, 4:08pm UTC](https://festim.discourse.group/t/convergence-plot/23/1 "2023-12-14T16:08:54Z")

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Hello, all!

Is it possible to export a convergence plot during FESTIM simulations? I also wonder if it is possible to do that separately for the H transport problem and the heat transfer problem.

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**Author:** ![remidm](https://yyz2.discourse-cdn.com/free1/user_avatar/festim.discourse.group/remidm/32/4_2.png) [@remidm](https://festim.discourse.group/u/remidm)\
**Post date:** [December 14, 2023, 4:25pm UTC](https://festim.discourse.group/t/convergence-plot/23/2 "2023-12-14T16:25:21Z")

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Hi @VVKulagin what exactly do you mean by a convergence plot?

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<div class="post-metadata">

**Author:** ![VVKulagin](https://yyz2.discourse-cdn.com/free1/user_avatar/festim.discourse.group/vvkulagin/32/51_2.png) [@VVKulagin](https://festim.discourse.group/u/VVKulagin)\
**Post date:** [December 14, 2023, 4:52pm UTC](https://festim.discourse.group/t/convergence-plot/23/3 "2023-12-14T16:52:30Z")

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@remidm. For a better clarity, I’ve thought of something similar to the convergence plot that Comsol Multiphysics produces during simulations. For Comsol, it is `reciprocal of step size vs. time step`.

For FESTIM, I’d be glad to have (and export) any metrics (that can characterise the convergence of the problem) vs. time step (or iteration).

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<div class="post-metadata">

**Author:** ![remidm](https://yyz2.discourse-cdn.com/free1/user_avatar/festim.discourse.group/remidm/32/4_2.png) [@remidm](https://festim.discourse.group/u/remidm)\
**Post date:** [December 14, 2023, 4:59pm UTC](https://festim.discourse.group/t/convergence-plot/23/4 "2023-12-14T16:59:23Z")

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This isn’t supported at the moment.  
But I think we could think of adding this as an export.

From what I remember, COMSOL shows these plots for each time step showing the error evolution as the number of Newton iterations increases. Is this what you’re talking about?

Since this is a discussion about new features, please open an issue on the FESTIM repository.

We will close this topic once we have a solution implemented.