Extract columns from matrices

I have a large number of .mat files, and each one contains three matrices named "matrx_1", "matrix_2" and "matrix_3" with different size.

I would like to extract, for example, the 6th and the 9th columns of each matrix "matrix_1" in two different arrays and then plot them. At the same time, I would like to repeat this operation for the 8th column of the matrix "matrix_2" and with the 10th column of matrix "matrix_3".

How can I do this? Thanks

[Adam]

What is wrong with just doing the obvious - load the mat files in a loop, index into the relevant matrices, store those columns and plot at the end? Are the matrices too big?

[Gaetano Pavone]

I'm a beginner in Matlab, could you post your suggestion please?

[Stephen23]

https://www.mathworks.com/help/matlab/import_export/process-a-sequence-of-files.html

https://www.mathworks.com/help/matlab/ref/load.html

I strongly recommend that you load into an output variable (which is a scalar structure).