# Time step representation in xvg files

**URL:** <https://gromacs.bioexcel.eu/t/time-step-representation-in-xvg-files/1076>\
**Category:** User discussions\
**Created:** [November 12, 2020, 10:37am UTC](https://gromacs.bioexcel.eu/t/time-step-representation-in-xvg-files/1076 "2020-11-12T10:37:34Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Harry](https://avatars.discourse-cdn.com/v4/letter/h/f6c823/32.png) [@Harry](https://gromacs.bioexcel.eu/u/Harry)\
**Post date:** [November 12, 2020, 10:37am UTC](https://gromacs.bioexcel.eu/t/time-step-representation-in-xvg-files/1076/1 "2020-11-12T10:37:34Z")

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GROMACS version: 2020.3  
GROMACS modification: No

BS"D

In a simulation with more than 1M steps, the time step column in the xvg file counting hbonds of gmx hbond starts using the 1e+06 format, after step 999,999. Not very desirable when I want to import that into matlab, or the like. Is there a way to stop that behaviour?

Thanks

Harry

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**Author:** ![hess](https://dub1.discourse-cdn.com/flex017/user_avatar/gromacs.bioexcel.eu/hess/32/416_2.png) [@hess](https://gromacs.bioexcel.eu/u/hess)\
**Post date:** [November 12, 2020, 2:13pm UTC](https://gromacs.bioexcel.eu/t/time-step-representation-in-xvg-files/1076/2 "2020-11-12T14:13:37Z")

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Note that that is the time, not the time step.  
You can change the %10g format string on line 3505 of src/gromacs/gmxana/gmx\_hbond.cpp to something else, for instance %10f

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<div class="post-metadata">

**Author:** ![Harry](https://avatars.discourse-cdn.com/v4/letter/h/f6c823/32.png) [@Harry](https://gromacs.bioexcel.eu/u/Harry)\
**Post date:** [November 15, 2020, 7:24am UTC](https://gromacs.bioexcel.eu/t/time-step-representation-in-xvg-files/1076/3 "2020-11-15T07:24:46Z")

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BS"D

Ok, thanks.