Matlab - save(int2str(i), x) doesn't work - Argument must contain a string

Question

I have a loop which is generating some data and in certain cases I want to save the data. Therefore I have:

save(int2str(i), x);

This doesn't work and comes out with the message:

??? Error using ==> save
Argument must contain a string.

What am I doing wrong?

Answer 1

The x has to be 'x':

 save(int2str(i), 'x');

Answer 2

Both the filename (in your case you correctly convert what I'm guessing is the loop index, i to a string) and the names of the variables that you want to save must be strings. You can save multiple variables to the same mat file by separating the variable names by commas. The Matlab documentation gives the following example . . .

savefile = 'pqfile.mat';
p = rand(1, 10);
q = ones(10);
save(savefile, 'p', 'q')