Assign matrix names using for loops in formula

Hi,

I was wondering how to get my code shorter and cleaner as I am basically using the same formula.

A = zeros(1,t);
B = zeros(1,t);
C = zeros(1,t);
D  = zeros(1,t);
E  = zeros(1,t);

for z = 1:1:t
    if z == 1
        A(:,z) = v1;
        B(:,z) = v2;
        C(:,z) = v3;
        D(:,z) = v4;
        E(:,z) = v5;
    else
    A(:,z) = A(:,z-1)*(1+rf);
    B(:,z) = B(:,z-1)*(1+rf);
    C(:,z) = C(:,z-1)*(1+rf);
    D(:,z) = D(:,z-1)*(1+rf);
    E(:,z) = E(:,z-1)*(1+rf);
    end
end

However, I am aware of better not to use eval.

But I do not get it working using an cell array like here with names = {'A' 'B' 'C' 'D' 'E'}. vx are just some values, which I coul also loop from an array.

Thanks in advance!

[Stephen23]

You are right to avoid eval, which is almost always a bad idea, especially with trivial looped code like this, no matter how much beginners seem attracted to using it:

http://www.mathworks.com/matlabcentral/answers/196952-how-to-create-new-variables-in-batches-with-strcat

The solution is to use indexing. That is all. There is no magic trick, just learn to use the dimensions of ND arrays, or cell arrays, or whatever array suits your needs, and use indexing.

Answer 1

[Jos (10584)]

Remember: It is the contents of the variable that should be flexible, not its name!

You will be way better off using arrays (regular, structs, or cells).

ABCDE = zeros(t, 5)
ABCDE(:,1) = [v1 v2 v3 v4 v5] ;  
for z = 2:1:t
    ABCDE(:,z) = ABCDE(:,z-1) .* (1+rf) ; % not sure what rf is, hence the .*
end