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fail to import data from csv file

Posted 29 apr 2015, 14:45 GMT-4 Parameters, Variables, & Functions Version 5.0 5 Replies

Yuankang Lu
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Dear colleagues,

I have some trouble loading data from a cvs file using the interpolation function. My file has 4 columns. First three columns are arguments (x,y,t) and the last one is the value of the physical quantity.

But when I try to import the file, an error message says : internal error in meshing initialization.

I attached the file here.
Any suggestions will be appreciated.
Thx

Attachments:

5 Replies Last Post 30 apr 2015, 16:44 GMT-4
Frank van Gool COMSOL Employee

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Posted: 1 decade ago 30 apr 2015, 04:02 GMT-4
Dear Yuankang,

As mentioned in the other thread on this subject:
www.comsol.nl/community/forums/general/thread/47735/

You need to make sure that the axis are in the same "order" because COMSOL maps the points to a grid.
You need to multiply your time column with 1e9, so that the values are in ns.

Best regards,
Frank
Dear Yuankang, As mentioned in the other thread on this subject: https://www.comsol.nl/community/forums/general/thread/47735/ You need to make sure that the axis are in the same "order" because COMSOL maps the points to a grid. You need to multiply your time column with 1e9, so that the values are in ns. Best regards, Frank
Gunnar Andersson COMSOL Employee

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Posted: 1 decade ago 30 apr 2015, 08:40 GMT-4

You need to make sure that the axis are in the same "order" because COMSOL maps the points to a grid.


This used to be true a couple of versions ago, but this requirement has been lifted - the data is scaled internally if necessary.

The most common reason for the error message is that the point set is singular. E.g., for a function of 3 arguments, the point set consists of points that all lie on a line or plane. Multiphysics' interpolation function code can't handle that.
[QUOTE] You need to make sure that the axis are in the same "order" because COMSOL maps the points to a grid. [/QUOTE] This used to be true a couple of versions ago, but this requirement has been lifted - the data is scaled internally if necessary. The most common reason for the error message is that the point set is singular. E.g., for a function of 3 arguments, the point set consists of points that all lie on a line or plane. Multiphysics' interpolation function code can't handle that.
Yuankang Lu
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Posted: 1 decade ago 30 apr 2015, 10:53 GMT-4
Dear Gunnar,

I did see some thread explaining the singulartiy of the set can be a problem when importing the data.
But in my case, all the points don't lie on a plan (If you go down to my data set, you ll see my third argument change).

I did what Frank suggested: multiple the third argument by 1e9 to make sure all the arguments are in the same or at least similar order. It works. It seems COMSOL hasn't lifted this requirement yet :(

Now I will try to use this three-argment function to set time and space dependent boudanry conditions.
Thank you guys for your help!

YK
Dear Gunnar, I did see some thread explaining the singulartiy of the set can be a problem when importing the data. But in my case, all the points don't lie on a plan (If you go down to my data set, you ll see my third argument change). I did what Frank suggested: multiple the third argument by 1e9 to make sure all the arguments are in the same or at least similar order. It works. It seems COMSOL hasn't lifted this requirement yet :( Now I will try to use this three-argment function to set time and space dependent boudanry conditions. Thank you guys for your help! YK
Daniel Connelly
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Posted: 1 decade ago 30 apr 2015, 16:36 GMT-4
It appears there's a hole in the data, near the point, at t = 1.2e-8

It appears there's a hole in the data, near the point, at t = 1.2e-8
Yuankang Lu
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Posted: 1 decade ago 30 apr 2015, 16:44 GMT-4
Oh really?
However I imported the data successfully. I ll check that. :0
Oh really? However I imported the data successfully. I ll check that. :0

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