Loading data with XML and NMD files

I have some vibration data that was acquired by a 3rd party system, then exported to Matlab.

There are 3 types of files generated: MAT, XML, NMD.

In the MAT file, I can access the data (structure) but it appears all 9 channels were 'multiplexed' into a single 1D array. I tried demultiplexing but to no avail. How do I extract the individual time traces?

[Mathieu NOE]

hi

can you share the file(s) ?

Answer 1

[Vatsal]

Hi Djamil Boulahbal,

I understand that you are working with a MAT file containing multiplexed data, where all the nine channels are combined into a single 1D array, and the objective is to demultiplex these channels and extract the individual time traces. To accomplish this, it is important to understand the data structure and how the channels were multiplexed.

Here's a general approach that you can try:

1) Begin by loading the data and using the "whos" command to view the variables and their sizes.

2) Create empty arrays to store the individual time traces.

3) Utilize indexing to extract the individual time traces from the multiplexed data array. The specific indexing method will depend on how the channels were multiplexed.

4) Finally, store the extracted time traces in the respective arrays created earlier.

I hope this helps!

Answer 2

[Djamil Boulahbal]

Thank you very much. I had already tried all you suggested and it did not work. It turns out that the person who saved the data did that with a third party software (nCode/Glyphworks) and such software had a bug where it did save only the first data channel. Thank again for the help.