# Symmetrical limits of axes (boxplot, QQ plot)

**URL:** <https://forum.certara.com/t/symmetrical-limits-of-axes-boxplot-qq-plot/2387>\
**Category:** Phoenix WNL basics\
**Created:** [March 17, 2012, 2:40pm UTC](https://forum.certara.com/t/symmetrical-limits-of-axes-boxplot-qq-plot/2387 "2012-03-17T14:40:17Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Helmut\_Schuetz](https://avatars.discourse-cdn.com/v4/letter/h/eb8c5e/32.png) [@Helmut\_Schuetz](https://forum.certara.com/u/Helmut_Schuetz)\
**Post date:** [March 17, 2012, 2:40pm UTC](https://forum.certara.com/t/symmetrical-limits-of-axes-boxplot-qq-plot/2387/1 "2012-03-17T14:40:17Z")

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It would be nice to have an option to automatically set symmetrical limits; maybe “Auto-scale Symmetrical”. Right now the automatic methods set the min / max based on the data ± some margin to generate a nice scaling. Especially for residual plots limits symmetrical around zero would be more informative, IMHO. Something like [color=#0000DD]AxisMin =-max(abs(data))-margin. AxisMax=+max(abs(data))+margin[/color] should do the job.