# Entropy calculation output

**URL:** <https://gromacs.bioexcel.eu/t/entropy-calculation-output/1877>\
**Category:** User discussions\
**Tags:** analysis-tools\
**Created:** [April 1, 2021, 3:09pm UTC](https://gromacs.bioexcel.eu/t/entropy-calculation-output/1877 "2021-04-01T15:09:03Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![daviddesancho](https://avatars.discourse-cdn.com/v4/letter/d/cdc98d/32.png) [@daviddesancho](https://gromacs.bioexcel.eu/u/daviddesancho)\
**Post date:** [April 1, 2021, 3:09pm UTC](https://gromacs.bioexcel.eu/t/entropy-calculation-output/1877/1 "2021-04-01T15:09:03Z")

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GROMACS version: 2020  
GROMACS modification: No

Hi  
I am trying to use the combination of gmx covar and gmx anaeig with the -entropy flag to calculate entropies for model peptides. The output I recover is a simple number for each of the methods available. I would need the time evolution of the value, in order to check whether the calculation is converging. Is there an option available to recapitulate that result?  
Thanks,

David

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**Author:** ![slovas](https://avatars.discourse-cdn.com/v4/letter/s/e274bd/32.png) [@slovas](https://gromacs.bioexcel.eu/u/slovas)\
**Post date:** [April 2, 2021, 3:35pm UTC](https://gromacs.bioexcel.eu/t/entropy-calculation-output/1877/2 "2021-04-02T15:35:29Z")

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To get the evolution of your entropy you need to calculate it cumulatively, depending on your simulation time, let’s say at 2 ns, 4 ns, … and plot it.

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**Author:** ![subrmani3127](https://avatars.discourse-cdn.com/v4/letter/s/ba8739/32.png) [@subrmani3127](https://gromacs.bioexcel.eu/u/subrmani3127)\
**Post date:** [May 16, 2025, 1:09pm UTC](https://gromacs.bioexcel.eu/t/entropy-calculation-output/1877/3 "2025-05-16T13:09:52Z")

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Can you please state how to do this cumulatively so that I can plot the data

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**Author:** ![daviddesancho](https://avatars.discourse-cdn.com/v4/letter/d/cdc98d/32.png) [@daviddesancho](https://gromacs.bioexcel.eu/u/daviddesancho)\
**Post date:** [May 16, 2025, 1:59pm UTC](https://gromacs.bioexcel.eu/t/entropy-calculation-output/1877/4 "2025-05-16T13:59:23Z")

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Easy! You can just write a for loop in your favourite scripting language invoking `gmx covar` with different (increasing) values of the flag `-e`. In this way you will include larger amounts of data in each calculation and eventually the estimate of the entropy will converge, provided you have sampled for long enough.