Getting a number of different outputs using a single function

Hi everyone.

I have created a function that can iteratively generate more sets of data from a smaller set of data through a random repetition. The following is the function I would like to change

% n is a multiplier/factor
% ExDataout, Erroru are outputs
% DataIn is the input

function [ExDataout,Erroru]=ExpandData(DataIn)
for m=1:100
    for n=1:5
    idx = sub2ind(size(DataIn), (1:size(DataIn,1))', randi(size(DataIn,2),size(DataIn,1),1));
    ExDataout(:,n*m) = DataIn(idx);
    Erroru=mean(ExDataout.').'-mean(DataIn.').';
    end
end

end 

I would like to get both the the output of the function depending on the value of n from the same function. For instance if n=1, I only have ExDataout(1) and Erroru(1). And if I have n=2, then I should have ExDataout(1), Erroru(1) as well as ExDataout(2), Erroru(2). Is there a way I could change this function to do exactly that?

Thank you.

Answer 1

[ANKUR KUMAR]

I have changed just the index where you are saving the output.

Focussing on "And if I have n=2, then I should have ExDataout(1), Erroru(1) as well as ExDataout(2), Erroru(2).": after each iteration of n, values are getting saved in Erroru and ExDataout.

That is why after 100 iteration of m and 5 iteration of n, you have 500 columns in the output.

First column in the output depeicts the values for m=1 and n=1.

Second column in the output depeicts the values for m=1 and n=2.

Thrid column in the output depeicts the values for m=1 and n=3.

Forth column in the output depeicts the values for m=1 and n=4.

Fifth column in the output depeicts the values for m=1 and n=5.

Sixth column in the output depeicts the values for m=2 and n=1.

Seventh column in the output depeicts the values for m=2 and n=2.

and so on...

[out1,out2]=ExpandData(randi(10,5,5))
function [ExDataout,Erroru]=ExpandData(DataIn)
for m=1:100
    for n=1:5
        idx = sub2ind(size(DataIn), (1:size(DataIn,1))', randi(size(DataIn,2),size(DataIn,1),1));
        ExDataout(:,(m-1)*5+n) = DataIn(idx);        
        Erroru(:,(m-1)*5+n) =mean(ExDataout.').'-mean(DataIn.').';
    end
end
end

Hope it helps.

[Lewis Waswa]

Thanks @ANKUR KUMAR. This however generates the last value of n. I am still trying to fingure out how to represent the EXDataout and Erroru as cells or 3D arrays that stores these values after each iteration.

[ANKUR KUMAR]

If you wish to save in a 3D array, you can use:

[out1,out2]=ExpandData(randi(10,5,5))
function [ExDataout,Erroru]=ExpandData(DataIn)
for m=1:100
    for n=1:5
        idx = sub2ind(size(DataIn), (1:size(DataIn,1))', randi(size(DataIn,2),size(DataIn,1),1));
        ExDataout(:,(m-1)*5+n,m) = DataIn(idx);        
        Erroru(:,(m-1)*5+n,m) =mean(ExDataout.').'-mean(DataIn.').';
    end
end
end

If you wish to save in a cell array, you can use:

[out1,out2]=ExpandData(randi(10,5,5))
function [ExDataout,Erroru]=ExpandData(DataIn)
for m=1:100
    for n=1:5
        idx = sub2ind(size(DataIn), (1:size(DataIn,1))', randi(size(DataIn,2),size(DataIn,1),1));
        ExDataout{m}(:,(m-1)*5+n) = DataIn(idx);        
        Erroru{m}(:,(m-1)*5+n) =mean(ExDataout.').'-mean(DataIn.').';
    end
end
end