extract time step filter doesn't seem to show the proper data

I am trying to understand how to deal with timesteps in paraview.
In order to do so, I applied 2 “extract time step filter” to data that has many timesteps in order to acces the information of 2 different timesteps.

When I first did it, it seemed to work, I mean, when I was turning on and off each of these “extract timesteps filters” the information shown in the render window was changing accordinagly. But, when I closed and opened the state afterwards it was not anymore the case, it didn’t matter which of these “extract timestep” filters was activated, the render view will always show the same timestep.

Moreover, when it seemed to work the first time (before closing and openening again the state when the render window was showing the proper timesteps when activated and deactivated) I applied an “append atributes” to these 2 “extract timestep” filters in order to have both of them accesible in the same wrench to be able to use a “calculator filter” that could call the variables of both timesteps, but the result of the operation was given wrong resutls, what could be wrong?

I will actually work with pvpython, but I was trying to do it first in the GUI mode in order to understand the mechanics of these filters.

Thank you very much


ParaView always display only one TimeStep at a time. The application allows to browse through the timesteps loaded from the reader.

  • Extract Time Steps only allows to use a subset of time when browsing time values from the application.
  • Force Time ignore the time asked by the application and always show the asked time (I think that what you expected in your test)
  • Temporal Array Calculator does simple operation on an array between two given timesteps.

See the Filters / Temporal menu for filters aware of timesteps manipulation.

Thanks very much for your reply,

Some time ago I did some basic operations with the temporal array operator, but now I am interested in having access to the data of 2 specific timsteps and do more complex operations between them, that’s why temporal array operator is not useful anymore in this case.
I tried now with force time, to be more precise, I applied 2 “force time” filters, then “append attributes” filter to these 2 “force time” filters. In this way I managed to have duplicated data in one pipeline with the data of 2 different timesteps. The problem comes now when I try to operate with this data with a “calculator” filter. I am getting the attached error message and the Result variable output from this calculator is not generated. I cannot get what it is happening because when I visualize the variables in the example “UNS_Ev_vol_input_1” and “UNS_Ev_vol” within the “append attributes filter” they look fine, i mean, It is clearly visible that each of these 2 variables correspond to the proper timespteps that I forced.

I see a PointDataToCellData in your pipeline but you ask for Point Data in your calculator : can you try to switch Attribute Type to Cell Data ?

Thanks again! I am working with point data because the filter “EpsilonAeroData1” you can see in the pipeline is a programmable filter that takes cell data and converts it into point data.
I attach an image of the data type output of the programmable filter “EpsilonAeroData”.

So, do you still have your problem ?

If yes:

  • check for typos
  • check that arrays exists in input with the correct attributes type (look in the Scalars and Vectors dropdown list)

Unfortunately I was not able to solve the error.

I entered the variables for the calculator in the example above by clicking them from the scalars dropdown list indeed.

I realized that the error is that the calculator is calling a different variable than the one I ask for.

I attach the data for the “append attributes” showed in the pictures I posted above. I saved it in vtk format (it is a clipped version of the data due to its big size, but error is still reproduced).

Normally, if you apply a calculator to this .vtk and for example just call the variable “ARNTZ_A” as the Result of the calculator, you will see that the Result data of the calculator does not correspond to the variable asked. (if this variable work ok, you can try with other ones, I am not sure if the varaibles failing are always the same). Thanks!

Edit: I am using Paraview 5.6.0.
I provided the case to a user of Paraview 5.10 and he was NOT able to reproduce the error.

for_paraview_discourse.vtk (2.3 MB)

Indeed, no problem for me with 5.10 …

I confirm, I updated from Paraview 5.6.0 to 5.10.1 and it works fine now.