[ab2484]

Dear All,

I have been looking for an answer to my simple question but I failed, so I am sure that you can help me.

I want to use the sampleDict dictionary to do some post-pro after the simulation is done Openfoam 4.X).
My simulation is transient and I want to check and plot some point values, so I'd like to have a .csv or .txt file including all my saved timesteps for a given point, like the utility Probes does.

Is that possible?

Thank you for your help,
Wishes

Andrea

[rajan19us]

Hi Andrea,

Try "Plot selection over time" Filter in Paraview and then export the graph in .csv file.


Regards,
Rajan

[ab2484]

Dear Rajan,

Thank for your reply.
Yes, I tried to locate some points and use that, but the fact is that I cannot chose the coordinates of the points, just guess their position manually.

[rajan19us]

Ahh....okay I am just a beginner in this topic. So the way I figured out to solve it is not so sophisticated (maybe experts know how to do it in a decent way).

Use "Extract location" to select the desired node and then by observing this node, you can use "Plot selection over time" filter to select the closest node.

I hope it was helpful.

Regards,
Rajan

[ab2484]

I am a begginner too, and I found your advice really usefull. Basically you search for a given point and then manually allocate a sampling point as close as possible to it, right?

Many thanks for you reply, if I find a different method I will keep you updated.

Kind regards

Andrea

[rajan19us]

Hi Andrea,

You're welcome.

Yes, that's exactly what I meant.

Regards,
Rajan

[blebon]

I wrote a Python script for that and it works like a charm:

from __future__ import print_function, division
from os import getcwd, environ, path, getenv, makedirs

import sys
import numpy as np
import pandas as pd

environ['PARAVIEWDIR']=getenv('HOME') + '/OpenFOAM/ThirdParty-4.1/build/linux64Gcc/ParaView-5.0.1'
environ['PYTHONPATH']=getenv('PARAVIEWDIR') + r';' + getenv('PARAVIEWDIR') + '/lib;' + getenv('PARAVIEWDIR') + '/lib/site-packages;'

for i in [getenv('PARAVIEWDIR'), getenv('PARAVIEWDIR') + '/lib', getenv('PARAVIEWDIR') + '/lib/site-packages']:
    if i not in sys.path:
        sys.path.append(i)

from paraview.simple import *
from paraview.numpy_support import vtk_to_numpy

SOURCE = OpenFOAMReader(FileName="case.foam")
SOURCE.MeshRegions = ['internalMesh']

probe = ProbeLocation(SOURCE, ProbeType = "Fixed Radius Point Source")
probe.ProbeType.Center = [0, 0, -0.06]  # probe location [x,y,z] <-- use coordinate you need to extract from here

# Loop through the files
probeResults = []
variable = 'p' # name of the array <-- use name of the variable to extract here
times = SOURCE.TimestepValues
# animationScene1.GoToFirst()
for time in times:
    print(time)
    #SOURCE.UpdatePipelineInformation()
    probe.UpdatePipeline(time)
    data = servermanager.Fetch(probe)
    probeResults.append(ns.vtk_to_numpy(data.GetPointData().GetArray(variable)))
    # animationScene1.GoToNext()

f = open('data.csv', 'w')

f.write('t (s), p (Pa)\n')
for i in range(len(times)):
   f.write("{0:10.5e},{1:10.5e}\n".format(times[i], probeResults[i][0]))

f.close()