Vectorization

A= 1000;   %amount borrowed
n= 12 ;    % number of payments per year

for r= 0.1 : 0.01 : 0.2
    fprintf ('%4.0f%' , 100*r ) ;
    for k = 15 : 5 25 
        temp = (1 + r/n) ^(n*k) ;
        P = r*A * temp / (n*(temp-1));
        fprintf ( '%10.2f' , P) ;
    end
end

How can I vectorized these two nested FORs ?

[Edited, Jan Simon, Code formatted]

Answer 1

[Andrei Bobrov]

A = 1000;
n = 12;
r = .1:.01:.2;
k = (15 : 5 :25).';
t1 = bsxfun(@(r,k)(1 + r/n) .^(n*k),r,k);
P1 = A*bsxfun(@times,r,t1 ./ (n*(t1-1)));
P = reshape([100*r;P1],1,[])

variant with one cycle

A = 1000;
n = 12;
r = .1:.01:.2;
k = 15 : 5 :25;
nr = numel(r);
nk = numel(k)+1;
out = zeros(1,nr + (nk-1)*nr);
for ii = 1:nr
    t = (1 + r(ii)/n) .^(n*k);
    out(nk*ii+(-3:0)) = [100*r(ii), A*r(ii)*t./(n*(t-1))];
end