function retuning the whole vector

I have a function that input a matrix and a vector

function s= solve(A, b) 
      for i=1:N
            s(i)=  something
      end
end

I want it to retunr the whole vector, like if disp(Solve(something)) would output a vector !

Can I use the return command here ?

Answer 1

[Walter Roberson]

That code outline already returns a whole vector. For example,

disp(mysolve(magic(6), [6;5;5;3;2;1]))

   385   347   381   439   455   435

function s = mysolve(A,b)
    for i = 1 : size(A,1)
        s(i) = dot(A(i,:), b);
    end
end

[Omar Keele]

I don't get it, I am getting only the first value of the vector at the ans variable, I just tried disp also and it display the same one value, however your function return the whole vector but I don't yet understand the difference between the two, here is mine :

function s= Solve(A, b)    %TODO argument control: A must have same size as b
    N= size(b,2);     
    % triangulation 
    for k= 1:N-1
        for i= k+1:N
            c= A(i,k)/A(k,k);
            b(i)= b(i)- c*b(k);
            for j= k:N
                A(i,j)= A(i,j)- c*A(k,j);
            end
        end
    end
    
    % 
    s(N)= b(N)/A(N,N);
    for i= N-1:-1:1
        sum= 0.0;
        for j= i+1:N
            sum= sum+ A(i,j)*s(j);
        end
        s(i)= (b(i)- sum)/A(i,i);
    end
end

[Walter Roberson]

In the code structure you posted, your upper limit of your for loop is N, but N is not shown as having a value. In your actual code how are you defining the upper limit?

[Omar Keele]

First line, N=size()

Is the order of filling the vector relevant?

[Walter Roberson]

You take size(b, 2) which is the number of columns in b. But suppose you were passed a column vector then the number of columns would be 1.