# How to update value of Cell only if its greater than the one in the last time step
**URL:** https://discourse.paraview.org/t/how-to-update-value-of-cell-only-if-its-greater-than-the-one-in-the-last-time-step/3693
**Category:** ParaView Support
**Created:** [February 28, 2020, 10:41am UTC](https://discourse.paraview.org/t/how-to-update-value-of-cell-only-if-its-greater-than-the-one-in-the-last-time-step/3693 "2020-02-28T10:41:39Z")
**Posts on this page:** 8
**Page:** 1
### Author:  [@Abbas](https://discourse.paraview.org/u/Abbas)
#### Post date: [February 28, 2020, 10:41am UTC](https://discourse.paraview.org/t/how-to-update-value-of-cell-only-if-its-greater-than-the-one-in-the-last-time-step/3693/1 "2020-02-28T10:41:39Z")
This is a bit difficult to explain so bear with me.
I have whole bunch of particles which change position and magnitude as time passes but I only want to update the magnitude if its bigger than the last-
i.e. I want each cell to hold the greatest magnitude it has had over the whole time series.
I know this might be easier than I think but my current knowledge of Paraview is a bit rudimentary and I would greatly appreciate your help!
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [February 28, 2020, 10:43am UTC](https://discourse.paraview.org/t/how-to-update-value-of-cell-only-if-its-greater-than-the-one-in-the-last-time-step/3693/2 "2020-02-28T10:43:27Z")
PlotDataOverTime ?
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### Author:  [@Abbas](https://discourse.paraview.org/u/Abbas)
#### Post date: [March 4, 2020, 7:04am UTC](https://discourse.paraview.org/t/how-to-update-value-of-cell-only-if-its-greater-than-the-one-in-the-last-time-step/3693/4 "2020-03-04T07:04:54Z")
So I tried the plotdataovertime but I want to apply a python calculator over a timeseries for each point- i.e something like a script to update values of each cell only if the value increases.
Would that be possible in the python calculator filter because from the little knowledge I have, I can only apply the script to deal with each timestep separately.
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [March 4, 2020, 7:44am UTC](https://discourse.paraview.org/t/how-to-update-value-of-cell-only-if-its-greater-than-the-one-in-the-last-time-step/3693/5 "2020-03-04T07:44:38Z")
No, only in a ProgrammableFilter using CONTINUE\_EXECUTING.
Not a trivial task if I’m being honest.
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### Author:  [@Abbas](https://discourse.paraview.org/u/Abbas)
#### Post date: [March 4, 2020, 7:51am UTC](https://discourse.paraview.org/t/how-to-update-value-of-cell-only-if-its-greater-than-the-one-in-the-last-time-step/3693/7 "2020-03-04T07:51:15Z")
I see.
I was wondering if I can apply the temporal shift filter to shift data one timestep back and then perform the needed comparison between the two sets of data?
Of couse this is with a rudimentary knowledge of the temporal shift filter and I would be grateful if you could guide me to any documentation of the programmableFilter.
Cheer
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [March 4, 2020, 7:52am UTC](https://discourse.paraview.org/t/how-to-update-value-of-cell-only-if-its-greater-than-the-one-in-the-last-time-step/3693/8 "2020-03-04T07:52:49Z")
You can easily compare timesteps with the ForceTime and the PythonCalculator, but you will not be able to integrate over time.
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### Author:  [@Abbas](https://discourse.paraview.org/u/Abbas)
#### Post date: [March 4, 2020, 7:56am UTC](https://discourse.paraview.org/t/how-to-update-value-of-cell-only-if-its-greater-than-the-one-in-the-last-time-step/3693/9 "2020-03-04T07:56:54Z")
So I can do it for one step but it wont be easy to do it for all? Is that because Forcetime can only take an absolute value and not a variable one like (n-1)?
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [March 4, 2020, 8:00am UTC](https://discourse.paraview.org/t/how-to-update-value-of-cell-only-if-its-greater-than-the-one-in-the-last-time-step/3693/10 "2020-03-04T08:00:55Z")
Yes.