# Amplitudes and conditional simulation

**URL:** <https://prepomax.discourse.group/t/amplitudes-and-conditional-simulation/1302>\
**Category:** General Questions\
**Created:** [December 1, 2023, 2:14pm UTC](https://prepomax.discourse.group/t/amplitudes-and-conditional-simulation/1302 "2023-12-01T14:14:40Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![dapineau](https://avatars.discourse-cdn.com/v4/letter/d/8e7dd6/32.png) [@dapineau](https://prepomax.discourse.group/u/dapineau)\
**Post date:** [December 1, 2023, 2:14pm UTC](https://prepomax.discourse.group/t/amplitudes-and-conditional-simulation/1302/1 "2023-12-01T14:14:41Z")

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Hello everybody.  
Two questions:  
1- Is there somewhere an example of using the Amplitude function?  
2- Is it possible to do a conditional simulation, that is to say for example a thermal simulation during which a temperature at a point reached would modify a boundary condition?

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**Author:** ![FEAnalyst](https://yyz2.discourse-cdn.com/free1/user_avatar/prepomax.discourse.group/feanalyst/32/688_2.png) [@FEAnalyst](https://prepomax.discourse.group/u/FEAnalyst)\
**Post date:** [December 1, 2023, 2:34pm UTC](https://prepomax.discourse.group/t/amplitudes-and-conditional-simulation/1302/2 "2023-12-01T14:34:07Z")

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> [@dapineau](#):
>
> 1- Is there somewhere an example of using the Amplitude function?

Here for dynamic analysis in time domain: [https://www.youtube.com/watch?v=R8HQKI3PTrI](https://www.youtube.com/watch?v=R8HQKI3PTrI)

> [@dapineau](#):
>
> 2- Is it possible to do a conditional simulation, that is to say for example a thermal simulation during which a temperature at a point reached would modify a boundary condition?

No, this would require Fortran subroutines. They are described in chapter 8 of CalculiX User’s Manual: [http://www.dhondt.de/ccx\_2.21.pdf](http://www.dhondt.de/ccx_2.21.pdf)

Temperature-dependent material properties can sometimes serve as a workaround in such cases.

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**Author:** ![ANYS](https://yyz2.discourse-cdn.com/free1/user_avatar/prepomax.discourse.group/anys/32/7737_2.png) [@ANYS](https://prepomax.discourse.group/u/ANYS)\
**Post date:** [December 1, 2023, 3:29pm UTC](https://prepomax.discourse.group/t/amplitudes-and-conditional-simulation/1302/3 "2023-12-01T15:29:30Z")

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First try to understand how amplitude work.

Then , you can do a first analysis to find when do you reach the desired temperature.  
Prepare an amplitude such that it is 0 up to that time and then 1 from there. Assign that amplitude to the variable you want to turn on at that precise time step.

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**Author:** ![dapineau](https://avatars.discourse-cdn.com/v4/letter/d/8e7dd6/32.png) [@dapineau](https://prepomax.discourse.group/u/dapineau)\
**Post date:** [December 1, 2023, 3:36pm UTC](https://prepomax.discourse.group/t/amplitudes-and-conditional-simulation/1302/4 "2023-12-01T15:36:55Z")

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Thank you very much!

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**Author:** ![dapineau](https://avatars.discourse-cdn.com/v4/letter/d/8e7dd6/32.png) [@dapineau](https://prepomax.discourse.group/u/dapineau)\
**Post date:** [December 1, 2023, 3:38pm UTC](https://prepomax.discourse.group/t/amplitudes-and-conditional-simulation/1302/5 "2023-12-01T15:38:15Z")

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Very good idea! THANKS!