Add .mat file checking

[GarronFish]

When using Modelica.Blocks.Sources.CombiTimeTable if a -v5 .mat file is used the model can crash with:
Error: The following error was detected at time: 0
InflateData: inflate returned data error

Could further details please be added to the error message, something like:
Check the file being read, supported formats for .mat files are -v4, -v6 and -v7

[beutlich]

What is a -v5.mat file according to this table: https://github.com/tbeu/matio/?issues/154#issuecomment-694923374 ?

Can you add the MAT-file here?

[GarronFish]

Apologies, I read the header of the .mat file and it says:
MATLAB 5.0 MAT-file, Platform: PCWIN64
This actually means -v6 or -v7 format which I did not realise.
Please close this ticket. I don't think I can provide a .mat file that shows this failure as the one I have contains sensitive information, and I don't want the client to have to spend a lot of time trying to create a non-sensitive data .mat file as the issue is sporadic. I think the workaround is to use the -v4 format. I think the issue is related to using int64 in the .mat file.

[beutlich]

Would be interesting how the MAT-file was created by which tool/framework/library.

Would also be interesting if MATLAB can load that MAT-file?

Generally speaking, it does not matter which version the MAT-file is, see for example this test

https://github.com/tbeu/ModelicaTableAdditions/blob/7677f73338f9aa9364e31ce9fa3e5a1d824855c5/ModelicaTableAdditions/Resources/Test/TablesFromMatFile.cc#L34-L37

[GarronFish]

The MAT-file was created using Matlab 2024b using save and the default settings. Ulf thinks the issue is related to the int64 array. There are about 200 arrays of size 9400 by 2 elements all real except one that is an int64 array.

Then a simple model with a Modelica.Blocks.Sources.CombiTimeTable table that reads a MAT file is run on Dymola 2025x Golden.

The error that occurs is:
Error: The following error was detected at time: 0
InflateData: inflate returned data error
The stack of functions is:
Modelica.Blocks.Types.ExternalCombiTimeTable
Modelica.Blocks.Types.ExternalCombiTimeTable((if combiTimeTable.tableOnFile then combiTimeTable.tableName else "NoName"), (if combiTimeTable.tableOnFile and combiTimeTable.fileName <> "NoName" and not Modelica.Utilities.Strings.isEmpty(combiTimeTable.fileName) then combiTimeTable.fileName else "NoName"), combiTimeTable.table, combiTimeTable.startTime/combiTimeTable.timeScale, combiTimeTable.co...

[beutlich]

That error "InflateData: inflate returned data error" normally indicates some file format violation. But could be a ModelicaMatio issue if the MAT-file was created by MATLAB.

W/o the file it's hard to tell what the actual issue is.

Can you please run matdump.exe -f whos path/to/file.mat

matdump.zip

[GarronFish]

This runs without a problem and displays information about the arrays stored in the .mat file, here is a snippet showing the int64 bit array.

[beutlich]

Would it help if I provide a stand-alone application - based on ModelicaStandardTables and ModelicaMatIO - that reads and prints a particular variable from a MAT-file for debugging purposes?

[GarronFish]

Would it help if I provide a stand-alone application - based on ModelicaStandardTables and ModelicaMatIO - that reads and prints a particular variable from a MAT-file for debugging purposes?

That would be great, it should help narrow down the cause of the issue.

[beutlich]

Please find ModelicaMatIODump in repo https://github.com/beutlich/ModelicaMatIODump

For your convenience I created a Win binary at https://github.com/beutlich/ModelicaMatIODump/actions/runs/20829618247

Running ModelicaMatioDump data/test_v7.mat tab1 dumps all values of the numeric array tab1 in the MAT-file.