# Interpolation tag history

**URL:** <https://forum.inductiveautomation.com/t/interpolation-tag-history/101575>\
**Category:** Ignition\
**Tags:** scripting\
**Created:** [January 29, 2025, 8:53pm UTC](https://forum.inductiveautomation.com/t/interpolation-tag-history/101575 "2025-01-29T20:53:33Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Ayanakoji](https://avatars.discourse-cdn.com/v4/letter/a/22d042/32.png) [@Ayanakoji](https://forum.inductiveautomation.com/u/Ayanakoji)\
**Post date:** [January 29, 2025, 8:53pm UTC](https://forum.inductiveautomation.com/t/interpolation-tag-history/101575/1 "2025-01-29T20:53:33Z")

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Is there any way to change the interpolation feature, instead of inserting imaginary values just used the previous value, because if I turn off interpolation if the value didn't change it will show zeroes.

for example (time,values) instead of this  
9am 5  
10am 6.5 (interpolaled value)  
11am 8

to this:  
9am 5  
10am 5  
11am 8

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<div class="post-metadata">

**Author:** ![lrose](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/lrose/32/62724_2.png) [@lrose](https://forum.inductiveautomation.com/u/lrose)\
**Post date:** [January 29, 2025, 9:11pm UTC](https://forum.inductiveautomation.com/t/interpolation-tag-history/101575/2 "2025-01-29T21:11:16Z")

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> [@Ayanakoji](#):
>
> Is there any way to change the interpolation feature

The only thing that you can do without "rolling your own", is change the Deadband Style and the Aggregation Mode.

> **[Configuring Tag History | Ignition User Manual](https://www.docs.inductiveautomation.com/docs/8.1/ignition-modules/tag-historian/configuring-tag-history#interpolated-values)**
>
> In 8.1.17, the Tag Editor was redesigned to improve usability. The new Tag Editor now requires fewer clicks and keeps relevant tag information visible while modifying bindings, alarms, and event scripts.

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<div class="post-metadata">

**Author:** ![Ayanakoji](https://avatars.discourse-cdn.com/v4/letter/a/22d042/32.png) [@Ayanakoji](https://forum.inductiveautomation.com/u/Ayanakoji)\
**Post date:** [January 29, 2025, 9:15pm UTC](https://forum.inductiveautomation.com/t/interpolation-tag-history/101575/3 "2025-01-29T21:15:28Z")

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im using last value on aggregation mode, but yeah it still about the deadband style but i dont want to use periodic since its inefficient.