# How can I accociate a parameter to each file?
**URL:** https://discourse.paraview.org/t/how-can-i-accociate-a-parameter-to-each-file/11691
**Category:** ParaView Support
**Tags:** vtk
**Created:** [March 23, 2023, 7:16pm UTC](https://discourse.paraview.org/t/how-can-i-accociate-a-parameter-to-each-file/11691 "2023-03-23T19:16:54Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@taratana](https://discourse.paraview.org/u/taratana)
#### Post date: [March 23, 2023, 7:16pm UTC](https://discourse.paraview.org/t/how-can-i-accociate-a-parameter-to-each-file/11691/1 "2023-03-23T19:16:54Z")
I am calculating coil current distribution in a cross-section and I successfully visualized the output at every time step with Paraview.
But I couldn’t associate a parameter that varies with time with every vtk file.
Is there any way to do that by just modifying vtk file? Maybe use global value? but I couldn’t find out how to use it.
For more clear discussion, I attached three vtk files. And I would like to store voltage like 10, 15, and -10 in the vtk files. Ultimately, I would like to annotate the value
[all\_data1.vtk](https://discourse.paraview.org/uploads/short-url/wEkY4sEcTscGpZK994Ofl0XRu8t.vtk) (638 Bytes)
[all\_data2.vtk](https://discourse.paraview.org/uploads/short-url/i7mJUSwy1HsfeoHvt5tPBLiMUuM.vtk) (639 Bytes)
[all\_data3.vtk](https://discourse.paraview.org/uploads/short-url/97pNW1g3Y2N6W7RwYGuvrSlu9PE.vtk) (637 Bytes)
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [March 24, 2023, 10:20am UTC](https://discourse.paraview.org/t/how-can-i-accociate-a-parameter-to-each-file/11691/2 "2023-03-24T10:20:29Z")
> [@taratana](#):
>
> But I couldn’t associate a parameter that varies with time with every vtk file.
PythonCalculator provide a `t_value` variable that you can use.