# Pens sumatory

**URL:** <https://forum.inductiveautomation.com/t/pens-sumatory/3365>\
**Category:** Ignition\
**Created:** [September 29, 2011, 11:52am UTC](https://forum.inductiveautomation.com/t/pens-sumatory/3365 "2011-09-29T11:52:17Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![SamJaimes](https://avatars.discourse-cdn.com/v4/letter/s/a6a055/32.png) [@SamJaimes](https://forum.inductiveautomation.com/u/SamJaimes)\
**Post date:** [September 29, 2011, 11:52am UTC](https://forum.inductiveautomation.com/t/pens-sumatory/3365/1 "2011-09-29T11:52:17Z")

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Hello,

How could you create a pen as a result of an average of other pens?

Thanks!

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**Author:** ![Travis.Cox](https://avatars.discourse-cdn.com/v4/letter/t/b9bd4f/32.png) [@Travis.Cox](https://forum.inductiveautomation.com/u/Travis.Cox)\
**Post date:** [September 29, 2011, 3:23pm UTC](https://forum.inductiveautomation.com/t/pens-sumatory/3365/2 "2011-09-29T15:23:04Z")

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Well, there is not a built-in function to the easy chart for that right now. However, you can create a DB expression tag that does something like:`({Path/To/Tag1} + {Path/To/Tag2}) / 2`You can set that tag to be stored historically and can display that on the easy chart.