ResampleWithDataset and extrapolate to nearby points

ParaView Support
1

Dear all,

grafik
grafik401×587 117 KB

This is the result of interpolating experimental data on a finite element mesh using ResampleWithDataset filter.
The missing points along the circle have value zero (blue in the contour above) because these points were not measured or have NaN.
However, the distance to the points living on the circle is small, so I want to extrapolate (nearest neighbor, bilinear, …) to have values everywhere.

Here is a state file containing the data and the output of the filter
state.pvsm (551.5 KB)

Here are the data (points and experimental values):
nodes.csv (7.4 KB)
data.txt (655.1 KB)

and the sequence of filters to generate the output
image

Is there any filter in paraview / pvpython that enables extrapolation or anything else I can do in paraview?

Thank you!

2

please share your data

3

@mwestphal I uploaded a state file in my question.

4

state file does not contains data Im afraid.

5

@mwestphal I uploaded the data manually and a screenshot how I apply the filter. Does this help?

6

Use a calculator to replace the NaNs with zero:

image
image2129×1635 257 KB

state.pvsm (719.2 KB)

7

I can not open the state file
ERROR: In vtkDelimitedTextReader.cxx, line 648

vtkDelimitedTextReader (0x17245b30): caught exception: Unable to open input file /home/glow/data/tmp/u2_325.txt

What is the calculator essentially doing? At the end, the values at the circle are still zero and no extrapolation happened.

8

@mwestphal My idea of extrapolation is not to replace the NaN’s by 0 but by a value related to the neighbor values, which are from 0.

Is that possible?

9

you obviously need to change the path to your own paths.

At the end, the values at the circle are still zero and no extrapolation happened.

Indeed, you can just remove the NaN point and let delaunay do its thing.

Here is a new version, you still need to change the path when you load the state:

image
image1920×1238 468 KB

state.pvsm (900.5 KB)

11

@mwestphal

I could reproduce the result in your state file. Basically, you have added an selection u>=0 followed by another delaunay. The trick is that the selection u>=0 gets rid of the NaN’s in my data, hence forcing the delaunay to triangulate the entire domain resulting in interpolation everywhere, even between the hole. Is it like that?

12

Exactly