ResampleWithDataset in batch python: output only some columns

ParaView Support
1

Dear all,

I wrote a python script to interpolate data using the ResampleWithDataset filter. I also want to output the result of the filter in a csv file. Here is what I tried:


resampleWithDataSet = ResampleWithDataSet(Input = ..., Source = ...)
writer = CreateWriter(myFile.csv, resampleWithDataSet)
writer.UpdatePipeline()

This works, but prints all columns, which are
“u”, “Points:0”, “Points:1”, “Points:2”, and “vtkValidPointMask”.
What I want is to output only the “u” column.

I thought the PassArrays filter helps and I tried

resampleWithDataSet = ResampleWithDataSet(Input = ..., Source = ...)
passArrays = PassArrays(resampleWithDataSet)
passArrays.RowDataArray = ['u']
writer = CreateWriter(myFile.csv, passArrays)
writer.UpdatePipeline()

But this outputs only “Points:0”, “Points:1”, “Points:2”. Regardless of what I write in
passArrays.RowDataArray = [‘u’], always the three columns are printed.

So is the PassArrays filer the right filter for outputting only some columns obtained from ResampleWithDataset ?

Thank you!

2

EDIT to my question:

I applied the Pass Arrays filter in the GUI to narrow down my problem and there is not even the possibility to not output the points:

Screenshot at 2023-11-06 09-16-07
Screenshot at 2023-11-06 09-16-071167×512 66.7 KB

As you can see, I can only uncheck the columns u and vtkValidPointMask within the Pass Arrays filter. Unchecking the Points column is not possible.
However, what I want is to output only the u column.

How can I do this?

3

Click on this button: a
and uncheck the points, then save as csv using this button: b

4

This is the way to go in the gui, but I have to achieve this with a python script since I do resampling for a bunch of files.

I can “Tools → Start Trace”, do your steps, “Stop Trace”, but this gives like 10-20 lines of script code.

Is there really no easier way to do this in python?

5

I’m afraid this is not possible in pvpython sadly. You would need to convert your dataset to a vtkTable but there is no such filter. It would be trivial to add though.

6

I see.

Out of curiosity: Why is the PassArrays filter not working here?

7

Because points are not an array in a dataset, they are points. You cant have a dataset without points. You need to convert to a table first, which contain only arrays and no geometry/topology.