Exporting large files to .mat

John Shishido

Posted on 09.02.2009 15:41
Hi all, When attempting to export data to a .mat file I get the following error: Access violation at address 049B1074 in module 'libmx.dll''. Read of address 00000040 in module "MatlabComm.WriteValue." Any suggestions as to how to correct this?
Jure Knez
Posted on 10.02.2009 00:24
The problem is in Matlab. Former versions of Matlab does not support files larger than 2 GB. Therefore the matlab function for exporting throws an error. Some sources claims that this limitation is gone with R14SP3 of Matlab, but we have tested with Matlab 2008 and larger files works well. The only way to correct this is to install latest Matlab on the machine where Dewesoft is installed. Then remove three files from Dewesoft.exe folder: libmat.dll, libmx.dll and libut.dll. Restart the computer and try again.
John Shishido

Posted on 11.02.2009 11:51
I have Matlab 2008b installed on my local machine. When I remove the three .dll files, DEWESoft throws an error due to a missing .dll file. When the three .dll files, the same access violation error comes up. Is there any other way to get around this? Do you have documentation for any other type of binary output file option?
Jure Knez
Posted on 12.02.2009 00:54
You have to restart the computer that Dewesoft takes the new libraries. For the binary file I suggest to wait few months for release of version 7 where the Dewesoft format will be open. Then it will not be needed anymore to export the data, but can directly import Dewesoft file in other packages...
John Shishido

Posted on 12.02.2009 08:57
What do you mean by 'new libraries'? I have installed Matlab 2008b on my local machine, removed the three .dl files from local DEWESoft viewer folder, and restarted. However when I try to export to a .mat file i get the following error: Export not possible. LIBMAT.dll library not found. It appears that DEWESoft viewer requires the .dll files. Is there any other way to export to a .mat, or am I still doing something wrong here?
Jure Knez
Posted on 19.02.2009 05:29
John, first apologize for late reply, our Matlab guru was ill and got back today. We have tried installing Matlab 2008 and delete the local libraries. The export works just fine after restart. We have been looking into it a bit deeper and found out possible reason why it fails. We are using LoadLibrary call for opening the files. This look in default folder, local folder, windows system folder, windows folder and then at last also in the folders defined by PATH variable. We have in the PATH also defined c:\program files\matlab\r2008a\bin\win32 folder, where the new libmat.dll and other needed files are located. Please run the command prompt (Run - Cmd) and enter Path command to see if the Matlab path is mentioned there. If not, add this path and it should work.
Charles Combs

Posted on 06.11.2012 22:17
I am experiencing exactly the same problem. Larger files won't export. You can see the file building to 2 GB, then it resets. I have removed the three .dlls, set the path in PATH, and restarted. I don't get an error when I export, it just doesn't work. I'm expecting that the .mat format would now used Matlab's default, which I confirm is MAT 7 format (which allows for 2 GB), but it does not.
Dewesoft Developer

Posted on 13.11.2012 13:13
We have added the new functionaly to Dewesoft Matlab export. Dewesoft can now export to Matlab 7.3 format. In order to do that you need to have installed Matlab R2006b or higher version (it must be 32 bit not 64). Then just delete the libmx.dll, libmat.dll, libut.dll from Dewesoft.exe folder and Dewesoft will automatically use newer version dll’s from installed Matlab folder. Matlab 7.3 format supports filers larger than 2 GB but it uses HDF format for storage so it will take much more space than format 5.0 which is compressed in case of Dewesoft. So if possible I w On 32 bit windows if one channel when exporting is larger than 2 GB it will still not work but here we can’t do much about it. Matlab versions: http://en.wikipedia.org/wiki/MATLAB This functionality was added in Dewesoft 7.1 b105. Best regards, Tilen.
Patrick Moser

Posted on 14.03.2016 08:26

Hi there,

I have a similar problem with the software. I am currently working with the DEWE800 with no programs installed except DEWESoft 7. When I try to export a data file (size: 11GB) to Matlab the error message "Not enough memory to perform export of data to matlab" occurs. The data file contains 15 channels but even if I try to export only one of these channels I get the same error. Do you have any idea how to solve this problem?

Kind regards,


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