How do I import a data file as a matrix and run a .m file from a python script?

I have a .m file that is used to run a neural network in matlab, which I have locally installed on my computer. I am trying to write a python script that will loop through a list of possible transfer and training functions for the neural network multiple times. I've written a function to open and edit the .m file, but I don't know how to; 1. run the .m file from the python script 2. import the necessary data for the neural network as a space delimited matrix.

I have three data files that need to be imported as matrices, what would the code look like?

Answer 1

[Walter Roberson]

To run the .m file, use

matlab -nodisplay -r "try YourScriptName; catch me; end; quit"

where YourScriptName is the file name without the .m file.

To read the data from space-separated columns, you can load() it.

Answer 2

[Mallory]

So is the code going to look like this, with the three files I have to load into matrices being NNinput, NNinputSiAvg340, NNoutput and the neural network file being NN_v1.m?

if true
import os
os.load('NNinput')
os.load('NNinputSiAvg340')
os.load('NNoutput')
matlab -nodisplay -r "try NN_v1; catch me; end; quit"
end

[Mallory]

woops, I'm a bit new to this forum, so ignore that 'if true' and 'end' part lol

[Walter Roberson]

Inside NN_v1.m you would have

NNInput = load('NNinput');
NNinputSiAvg340 = load('NNinputSiAvg340');
NNoutput = load('NNoutput');

followed by configuring and training and whatever-else using those three matrices.

[Mallory]

Okay, I put that into the NN_v1.m script, put when I run a python script with just the line

matlab -nodisplay -r "try NN_v1; catch me; end; quit"

Does it make a difference that I'm on linux? It probably does...I'm terribly sorry I didn't mention that before.

[Mallory]

I have matlab2013a, located at /usr/local/MATLAB/R2013a/

[Walter Roberson]

No, that should work fine in Linux.

You can redirect output using the standard ">" redirection, if you want.

What are you seeing when you try this above ?

Answer 3

[Mallory]

Figured it out!

os.system("matlab -nodisplay < NN_v1.m")

Thanks for your help Walter!

[Walter Roberson]

Better would be

os.system("matlab -nodisplay -r 'try NN_v1; catch me; end; quit'")

When you redirect from a script, sometimes you end up with MATLAB endlessly asking for more input. And the try/catch/quit helps in case something goes wrong with the script.