Time Sync between two datasets

Hello,
I am reviving a problem, see screen shots below, which I have come across:


I cannot see a resolution of this problem – which seems to be a recognized problem in paraview.

I am an end user, so all I need is an example of how to synchronize two datasets in paraview as an end user.

Please treat as urgent as I cannot progress without its resolution.

Thank you
Nadeem Malik

The bug you are referring to (#17097) was resolved 5 years ago. It was resolved by adding the Synchronize Time filter. This filter synchronizes the time stamps of one data set with the reported time stamps of another one.

If that filter does not solve the problem you are referring to, you will need to be more specific about the issue that you are having.

That is good news.

But can you tell me how to apply the Synch Time Filter inside paraview – I have not done this before and I am also relatively new to Paraview.

Currently, within paarview I am read in 60 datafiles of flow data (say flow.f00001 — flow.f00060) in *.nek5000 format, and then 60 datasets of particle motions (say par00001.vtu – par00060.vtu) in *.vtu format. I create a *.pvd file that simply lists the timesteps from 0.000000E+00 to 6.000000E+00.

I can see extra files, with some double defined e.g. “0.8” and “0.8”. The flow and particles run ok on their own, but not when I run them together.

So how and when do I apply the Time Filter – is there an example available. Even better, is there a video example?

Thanks
Nadeem

I think we should back up to make sure we are solving the correct problem. I’m not sure what you are trying to solve has much to do with the #17097 issue you originally referenced.

You should know that when you load 2 or more data sets with time data, ParaView will automatically synchronize the time steps. No further steps are required, it will just work.

However, the precondition of having this work is that all the data files tag each timestep with the proper simulation time, and the time is consistent across all files. This is not always the case. For example, .vtu files do not have the ability to record a time value, so when you load a series of these files, you just get timesteps of 0, 1, 2, etc., which are unlikely to match the simulation time. If this is the case, you have to fix your data to have the correct timestep. For something like .vtu, which has no time steps, you have to wrap it in something like a .pvd or .series file that allows you to specify the time stamp.

#17097 was solving the more specific problem where two files had timestamps that were nearly identical, but due to floating point inaccuracies registered as separate times. That would show up as timesteps that looked repeated. If that is not your issue, then don’t worry about that.

Hmmm, looks like the 2nd problem.

So say I have files *.f0001 etc which have a time stamps and also I presume file numbers, and I have parallel *.vtu files with no timestamps but do have file numbers.

On this basis I would only need to work in terms of file numbers in paraview?

Is there a way of working in terms of file number only in Paraview?

Thanks
Nadeem