How would I create a 3D matrix with channels, epoch time-series data, and trials as the dimensions?

1

I am looking for a way to create a data matrix to use for our analysis. I need to write a script that creates a matrix containing this information:

[ 
    [ 
         % trial 1
         epoch 1 time-series for channel 1, 
         epoch 1 time-series for channel 2,
         epoch 1 time-series for channel 3,
         ....
         ....
         ....
     ],
     [  
         % trial 2
         epoch 2 time-series for channel 1, 
         epoch 2 time-series for channel 2,
         epoch 2 time-series for channel 3,
         ....
         ....
         ....
     ],
     ....
     ....
     % for all 810 trials
]

I have already preprocessed the data and created the epochs in brainstorm so those epoch files are in a folder in the database on my computer. Is there a way to create the above matrix in MATLAB?

Thank you for any help!

2

I think this is what the process example "process_example_customavg.m" does:
Tutorials/TutUserProcess - Brainstorm

If you are not familiar with Brainstorm scripting yet, starting with the Scripting tutorial would probably help:
https://neuroimage.usc.edu/brainstorm/Tutorials/Scripting

1 Like
3

Hi James,

Not quite sure exactly what you want your array to look like but it seems like you are looking to generate something like the below figure.

To generate a multidimensional array like this you should visit the following.

image

1 Like
4

This seems like exactly what I need! Thanks so much.

5

Hello, I got your solution to work which included using the "files to process" box to generate a selection of files with the tag of my event name. This opened a matlab file and at the top it had

sFiles = {Subject01/...... , 
          Subject02/...... , 
          etc. for 800+ epochs}

which lists all of the epoch files that don't contain bad segments of data.

I need to do this for multiple subjects though so I was wondering if there is a way to produce this list of good trials without first using the "files to process" box.

Is there a way to write a script to get the same epochs that are present in sFiles using only a script?

6

You can start from an empty Process1 box, and start your script with the file selection, with the processes Files > Select files: *.