How to image 2D data in txt file

Changwan_Sun · May 23, 2022, 5:39am

Dear all,

I can read a 2D text file with your kind answers for many questions. But, I do not know the next step, how to visualize the matrix in the Paraview. My data has this structure, 81 x 4096 matrix.

I followed this step:

opened the text file with Delimited text (CSV Reader).
changed the properties: deactivate the have headers.
changed the properties: " " in the Field Delimiter Characters.
changed the properties: activate the Merge Consecutive Delimiters
click “Apply”
click the filter, Table to Points, in the Filters tap.

After this list of steps, I do not know how to image the matrix.

When I click the X column or Y or Z, this show many fields. This data is only 2D data. Then I need two axes.

How can I image those fields?

I expect this kinds of image (some part of the matrix, ), which was visualized by gnuplot.

My final goal is to image 3D matrix in the Paraview. As a basics step, I hope to understand how to image the 2D matrix in the Paraview.

Help me out please!!

Thank you for reading this topic.

Christos_Tsolakis · May 24, 2022, 2:30am

Check the Filter properties. X Column, Y Column should be mapped to the appropriate column of your table. Currently both of them point to Field 0. Check also the 2D Points checkbox. You can then use Delaunay2D and PointDatatoCellData to create an image similar to the one from gnuplot. See below

Even simpler you can use the TableToStructuredGrid Filter see:

Changwan_Sun · July 5, 2022, 7:50am

Sorry for too late reply. I totally forgot this posting. Thank you for your nice answer! I will try this!

Changwan_Sun · September 3, 2022, 7:41am

Hi, It’ been a while from your nice reply. Now I have been following the steps that you suggested.

My data set has the structure, 616 x 1547 (row x column).

You suggested to assign some field to each column. But I need all the field.

2.When I use the TableToStructure, I found this error message:

vtkTableToStructuredGrid (0x7f7de8017740): The input table must have exactly 1 rows.

How to use all the rows and all the columns?

Changwan_Sun · September 3, 2022, 8:24am

I am trying smaller dataset with simple structure: 4 x 10 (row x column).
test_paraview.txt (111 Bytes)

How to image this file in Paraview?

Changwan_Sun · September 5, 2022, 5:43am

I finally knew to image the 3D-structure text file by using paraview.
I followed this way to get the vtk file:

github.com

pyscience-projects/pyevtk/blob/master/examples/image.py

#! /usr/bin/env python

# ***********************************************************************************
# * Copyright 2010 - 2016 Paulo A. Herrera. All rights reserved.                    *
# *                                                                                 *
# * Redistribution and use in source and binary forms, with or without              *
# * modification, are permitted provided that the following conditions are met:     *
# *                                                                                 *
# *  1. Redistributions of source code must retain the above copyright notice,      *
# *  this list of conditions and the following disclaimer.                          *
# *                                                                                 *
# *  2. Redistributions in binary form must reproduce the above copyright notice,   *
# *  this list of conditions and the following disclaimer in the documentation      *
# *  and/or other materials provided with the distribution.                         *
# *                                                                                 *
# * THIS SOFTWARE IS PROVIDED BY PAULO A. HERRERA ``AS IS'' AND ANY EXPRESS OR      *
# * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF    *
# * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO      *
# * EVENT SHALL <COPYRIGHT HOLDER> OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,        *
# * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,  *

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Thank you for everyone that read my post.