Extract and plot cell centrered only data in plot over line

ParaView Support
1

Hi,
Been using paraview for a long time (probably going to regret saying that). Anyway, I have a cell-data only solution on a cgns mesh.

Firstly, I want to plot over a line on the mesh and see only the data from the cells: not edges, points, or from interpolation in the graph window.

Secondly, when I’m happy I have the plot I want, I want to save the data to a csv.

I cannot for the life of me get this to work, unless in the plot over line section: Attribute type is “Point Data” which places data points on the graph that are not in my solution. Changing to “Cell Data” what I would assume I should use, gives an empty plot. Likewise, when saving the data, either with the Point/Cell Data attribute set, if I pick anything but Point Data in the csv dialogue box, I get empty an csv files.

I am really sure I used to be able to do this. I’m trying to find a problem and I’m looking for subtle inconsistencies, having interpolated solution data added (useful in some instances I grant you) is not what I want at present.

Finally, for a bonus question if the above gets resolved, what interplay does the resolution dialogue box then have when one only wants to plot the actual solution data (cell-centered in this instance) from the simulation and not interpolated data? I have about 65 cells along the plot over line vector, stretched in a boundary layer. Currently, I always leave the default to 1000, so clearly there will be repeated data if I pick “Cell Data”, is that correct?

Any help really appreciated. Latest version of paraview. Hopefully this is just a simple mistake by me…
Thanks again,
Andy

2

Do you mean that there are points along the x axis that are not in your data set? That is expected as the Plot Over Line filter works by defining a set of sample points in space (by default, 1000, specified by the Resolution property) and then sampling the data at those points. For cell data, there should be no interpolation of the data value happening. The sampled data is defined as Point Data in the output because the values are associated with the sample points, which is why you see the sampled data in the Point Data attribute and not the Cell Data attribute.

It is easy to imagine a version of this filter that would compute line segments within each of your cells and then associate a cell-centered value with them, but that is not how this filter works (nor was it ever to my knowledge - happy to be proven wrong). In addition, I don’t believe the plotting capabilities in ParaView could handle this type of data properly, but it does handle point plotting.