# performing some mathematical operation on each time steps separately and then subtract the two time steps datas.

**URL:** https://discourse.paraview.org/t/performing-some-mathematical-operation-on-each-time-steps-separately-and-then-subtract-the-two-time-steps-datas/5625
**Category:** ParaView Support
**Tags:** python, vtk
**Created:** [October 22, 2020, 1:27pm UTC](https://discourse.paraview.org/t/performing-some-mathematical-operation-on-each-time-steps-separately-and-then-subtract-the-two-time-steps-datas/5625 "2020-10-22T13:27:01Z")
**Posts on this page:** 5
**Page:** 1

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### Author: ![nvdmt](https://discourse.paraview.org/user_avatar/discourse.paraview.org/nvdmt/32/5173_2.png) [@nvdmt](https://discourse.paraview.org/u/nvdmt)
#### Post date: [October 22, 2020, 1:27pm UTC](https://discourse.paraview.org/t/performing-some-mathematical-operation-on-each-time-steps-separately-and-then-subtract-the-two-time-steps-datas/5625/1 "2020-10-22T13:27:01Z")

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Hi everyone,

First of all, I need to mention that I am totally new on this forum and a bit newbie in using ParaView. So please forgive me if I am not writing professionally.

My question is how can I load a single mesh containing two time steps and separately, operate different mathematical operations on each of the time steps, and finally subtract the two modified time steps datas from each other. Is there any specific filter to do so or I need to write a script.

Thank you in advance for your help  
Navid

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### Author: ![mwestphal](https://discourse.paraview.org/user_avatar/discourse.paraview.org/mwestphal/32/17_2.png) [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [October 22, 2020, 1:40pm UTC](https://discourse.paraview.org/t/performing-some-mathematical-operation-on-each-time-steps-separately-and-then-subtract-the-two-time-steps-datas/5625/2 "2020-10-22T13:40:42Z")

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Welcome !

Sounds like a job for the temporal operator filter.

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### Author: ![nvdmt](https://discourse.paraview.org/user_avatar/discourse.paraview.org/nvdmt/32/5173_2.png) [@nvdmt](https://discourse.paraview.org/u/nvdmt)
#### Post date: [October 22, 2020, 1:51pm UTC](https://discourse.paraview.org/t/performing-some-mathematical-operation-on-each-time-steps-separately-and-then-subtract-the-two-time-steps-datas/5625/3 "2020-10-22T13:51:38Z")

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Thank you for your reply!

By “temporal operator” if you mean temporal array operator, I tried that one, but it was useful only when I wanted to apply basic mathematic operations between both time steps.  
What if prior to that, I need to multiply a constant number by only one of the time steps?

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### Author: ![Andrei](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/a/9fc29f/32.png) [@Andrei](https://discourse.paraview.org/u/Andrei)
#### Post date: [October 22, 2020, 2:39pm UTC](https://discourse.paraview.org/t/performing-some-mathematical-operation-on-each-time-steps-separately-and-then-subtract-the-two-time-steps-datas/5625/4 "2020-10-22T14:39:48Z")

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Maybe this information will be useful to you [How to subtract time(t) data from time(0) data](https://discourse.paraview.org/t/how-to-subtract-time-t-data-from-time-0-data/130) . `Force Time` filter to extract data for specific steps. `Append Attributes` filter to combine data. `Calculator` for operating

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### Author: ![nvdmt](https://discourse.paraview.org/user_avatar/discourse.paraview.org/nvdmt/32/5173_2.png) [@nvdmt](https://discourse.paraview.org/u/nvdmt)
#### Post date: [October 22, 2020, 3:06pm UTC](https://discourse.paraview.org/t/performing-some-mathematical-operation-on-each-time-steps-separately-and-then-subtract-the-two-time-steps-datas/5625/5 "2020-10-22T15:06:30Z")

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Thank you Andrdei! That was exactly what I needed. It worked perfectly.