How to update workspace variable content for every iteration?

Hi,

So I have this code

h = SomeFunction;
h.run
for i = 1:4
    data_local = h.data;
    data_local = data_local+rand(1)
    plot(data_local);
    pause(2);
end

which outputs 128x25 matrix every second(with a time gap of 2 secounds)

so for each iteration I want this to update the variable in the work space so i used

assignin('base','data',data_local)

inside the loop.

this seems to work, but the thing is only the last value is being stored (after the loop is completed).

Can anyone tell me how to update the variable in the workspace on each loop?

thanks in advance.

[Stephen23]

Are you running this code from a script or in the MATLAB command window?

[Stephen23]

Do not use the variable names i or j for the names of loop variables, as these are both the names of the inbuilt imaginary unit .

Answer 1

[Stephen23]

You did not state in your question how you are runing this code, so I assumed that it is in a script. You can store the output of each iteration in an array, possibly a cell array , like in this example:

h = SomeFunction;
h.run
out = cell(1,4);
for k = 1:4
    out{k} = h.data + rand(1);
    plot(out{k});
    pause(2);
end

You will find all of the data in the cell array out. Cell arrays use their own special indexing .

Another method would be to store it in a simple numeric array, which might make some later processing much easier as you could use vectorized operations on the complete array:

h = SomeFunction;
h.run
out = nan([size(A.data),4]);
for k = 1:4
    out(:,:,k) = h.data + rand(1);
    plot(out(:,:,k));
    pause(2);
end

Also I changed the name of your loop variable to k. Do not use the variable names i or j for the names of loop variables, as these are both the names of the inbuilt imaginary unit .

[akshay raj]

Hi Stephen,

Thanks for the reply. I am running this as a script. I did try your code, it is working but i am not able to see the the variable content in the workspace, if this happens i could reuse the data and save it in a separate file or i could use this in a different function.

so this is the actual link of the files that i am using.

thank you.

[Stephen23]

If you run this as a script then the variables must be in the base workspace, as this is the one and only workspace that scripts use. What do you mean "not able to see the the variable content in the workspace" ? Can you see the variables in the workspace? Is your workspace panel open (or docked, or undocked and hiding..)? Did you try double-clicking on the variable in your workspace?

Please run the script, and then upload a screenshot of your MATLAB window.

[akshay raj]

sorry this is actually a function, and I think i just need to put the out variable inside

function [out] = fileName

thank you soooooo... much for your help. this works.