Save and Load a matrix

Hello, I know this a general question but I am having trouble with saving a matrix and loading it into another code. I do;

save('vzpre1','vz');   % The variable is vz and I save as vzpre1. I just want to save only vz matrix nothing else

vz=load('vzpre1');     % I want to load vzpre1 as vz.

But once I load it. It loads as struc not a matrix.

Any idea?

Thanks

[Nicle Davidson]

Try this:

save('vzpre1','vz'); 
load('vzpre1','vz'); 
%also use vzpre1.mat instead of just vzpre1, so this code instead:
save('vzpre1.mat','vz'); 
load('vzpre1.mat','vz'); 
%so you use a .mat file for this transaction

[Stephen23]

Do NOT just LOAD directly into the workspace. That approach is fine when experimenting at the command window, but not for code that you write in scripts or functions (i.e. when you want reliable, repeatable code).

It is much more robust to LOAD into that structure and then access its fields. That is what experienced MATLAB users do.

Answer 1

[DGM]

I don't know why nobody has thrown an answer here, but here goes.

The output argument of load() is a struct. You either use the struct contents as they are, or you can assign them to new variables if it makes using them easier.

vz = rand(100); % a matrix

save('vzpre1','vz'); % write the variable to vzpre1.mat

S = load('vzpre1'); % read mat file into a struct
vzfromthefile = S.vz; % explicitly define the incoming variables

immse(vz, vzfromthefile) %show that the two arrays are identical

ans = 0

The command syntax for load avoids this step and might seem inviting, but is generally discouraged for good reason.

https://www.mathworks.com/matlabcentral/answers/304528-tutorial-why-variables-should-not-be-named-dynamically-eval#answer_274740