# Changing an analysis parameter during cycling

**URL:** <https://forum.itascainternational.com/t/changing-an-analysis-parameter-during-cycling/1247>\
**Category:** Uncategorized\
**Created:** [November 14, 2023, 1:14pm UTC](https://forum.itascainternational.com/t/changing-an-analysis-parameter-during-cycling/1247 "2023-11-14T13:14:50Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![cgulenc](https://avatars.discourse-cdn.com/v4/letter/c/71c47a/32.png) [@cgulenc](https://forum.itascainternational.com/u/cgulenc)\
**Post date:** [November 14, 2023, 1:14pm UTC](https://forum.itascainternational.com/t/changing-an-analysis-parameter-during-cycling/1247/1 "2023-11-14T13:14:50Z")

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Is it possible to change a parameter during cycling in FLAC3D?

For example, I want to check the effective stress value at a zone or the shear force value at a structural element at each time step or at specific time intervals. When running the analysis, I want to change the stiffness/strength parameter of the zone/structural element based on the level of the value I checked.

Can it be done by fish scripting?

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**Author:** ![cheng](https://avatars.discourse-cdn.com/v4/letter/c/ecccb3/32.png) [@cheng](https://forum.itascainternational.com/u/cheng)\
**Post date:** [November 15, 2023, 4:16pm UTC](https://forum.itascainternational.com/t/changing-an-analysis-parameter-during-cycling/1247/2 "2023-11-15T16:16:23Z")

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Yes, fish-call does the job. Refer to the doc of [fish-call](https://docs.itascacg.com/itasca900/common/kernel/doc/manual/model/commands/cmd_model.solve.html?highlight=fish-call#kwd:model.solve.fish-call) under the command [model solve](https://docs.itascacg.com/itasca900/common/kernel/doc/manual/model/commands/cmd_model.solve.html?node1023).

The command [fish callback](https://docs.itascacg.com/itasca900/common/kernel/doc/manual/fish/commands/cmd_fish.callback.html#command:fish.callback) is helpful as well.

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<div class="post-metadata">

**Author:** ![cgulenc](https://avatars.discourse-cdn.com/v4/letter/c/71c47a/32.png) [@cgulenc](https://forum.itascainternational.com/u/cgulenc)\
**Post date:** [November 16, 2023, 9:04am UTC](https://forum.itascainternational.com/t/changing-an-analysis-parameter-during-cycling/1247/3 "2023-11-16T09:04:21Z")

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Great! Thank you very much.