Exporting large files to .mat

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?

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.

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?

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...

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?

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.

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.

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.