How to make a .m file read an input csv file passed as a parameter?

Question

I am new in Matlab and facing difficulty in making a .m file read the input csv file that I am passing as an argument from the command prompt. I understand that a function has to be written to read the input file as a parameter. Here is the code I wrote inside the .m file to accept the input file:

function data=input(filename);
addpath(genpath('./matlab_and_R_scripts'));
tic
D=csvread(filename,1,1);

I want the filename passed as an argument to be read by the function "csvread" and save it in D. I am using the following command to execute the script:

matlab -nodisplay -nosplash -nodesktop -r "input 'exp2_1_DMatrix.csv';run('matlab_filename.m');exit;"

I am able to execute the script without any errors but it is not reading the input file as the downstream analysis should have saved a new file if it was able to read the file and execute some functions on it.

Can anyone please suggest how to read the input file in my matlab script and the proper command to pass?

Answer 1

Try using this function. Take care on not using reserved names:

readdat.m

function data=readdat(filename);
addpath(genpath('./matlab_and_R_scripts'));
tic;
data=csvread(filename,1,1);
toc;

For testing, you can execute this function directly in the Command Window and editing in the Matlab Editor, which is where most functions, most of the time, are tested until you are fully satisfied with your processing.

>> data=readdat(filename);

Looking at data you can realize if the file was or not read as it should.

>> data(:,1)

You can keep running other scripts, such as matlab_filename.m. But the best choice is having a function working with everything:

processdat.m

function data=processdat(filename)
% Original Function
addpath(genpath('./matlab_and_R_scripts'));
tic;
data=csvread(filename,1,1);
toc;
% Paste in here all the matlab_filename.m code, or do a call:
matlab_filename;
% Do not uncomment this exit in here, since you want to keep working until the function do what you need
% exit;

Later, if you want some serious automation and want some programming tasks having repetitions of your code under some schedule, you can of course arrange a Windows bat command, and in this case, you can uncomment that exit; terminator at the end of processdat.m.

processdat.bat

 matlab -nodisplay -nosplash -nodesktop -r processdat

Remember to ensure the OS can access matlab, and that Matlab can access processdat. If in doubt, place the proper paths:

processdat.bat

 c\programs\bin\matlab -nodisplay -nosplash -nodesktop -r c\files\processdat.m