# Chart interpolation **URL:** \ **Category:** Ignition\ **Created:** [August 14, 2017, 5:40pm UTC](https://forum.inductiveautomation.com/t/chart-interpolation/15059 "2017-08-14T17:40:46Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![johnny.alvarado](https://avatars.discourse-cdn.com/v4/letter/j/dc4da7/32.png) [@johnny.alvarado](https://forum.inductiveautomation.com/u/johnny.alvarado)\ **Post date:** [August 14, 2017, 5:40pm UTC](https://forum.inductiveautomation.com/t/chart-interpolation/15059/1 "2017-08-14T17:40:46Z")
If you see the attached image ![](https://us1.discourse-cdn.com/inductiveautomation/original/2X/f/f68e85257936fc8974bf7426f3ea412fab8d5950.png) The first tag is interpolated linearly, but the other two are interpolated stair step. I did nothing different for each one, so how can I control the interpolation type with the chart component? ---
**Author:** ![paul-griffith](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/paul-griffith/32/37249_2.png) [@paul-griffith](https://forum.inductiveautomation.com/u/paul-griffith)\ **Post date:** [August 14, 2017, 6:02pm UTC](https://forum.inductiveautomation.com/t/chart-interpolation/15059/2 "2017-08-14T18:02:35Z")
This looks like it might be related to a bug ticket I just filed. Are these populated by a tag history query? I don’t have a workaround yet, but I’ve added you to the internal bug ticket so I’ll hopefully remember to update this thread once there’s an update on the ticket. ---
**Author:** ![johnny.alvarado](https://avatars.discourse-cdn.com/v4/letter/j/dc4da7/32.png) [@johnny.alvarado](https://forum.inductiveautomation.com/u/johnny.alvarado)\ **Post date:** [August 14, 2017, 8:20pm UTC](https://forum.inductiveautomation.com/t/chart-interpolation/15059/3 "2017-08-14T20:20:06Z")
Yes, the chart information is populated by a tag history query. How long does a bug ticket takes to be solved?