How can I make this faster?

I always try not to use for loops but I do not know how to avoid the for loop to do this:

   n=1000;
   m=100;
   A=rand(n,m)+rand(n,m)*1j;
   tic
   B=zeros(100);
   for ii=1:n
       B=A(ii,:)'*A(ii,:);
       C(ii,:)=B(:).';
  end
  toc

thanks in advance,

Ignacio

Answer 1

[Orion]

just start by preallocate some memory for C :

clear C C2 B
n=1000;
m=100;
A=rand(n,m)+rand(n,m)*1j;

tic
B=zeros(m);
for ii=1:n
    B=A(ii,:)'*A(ii,:);
    C(ii,:)=B(:).';
end
toc

tic
C2 = zeros(n,m*m);
for ii=1:n
    C2(ii,:) = reshape(A(ii,:)'*A(ii,:),1,m*m);
end
toc

isequal(C,C2)

=>

Elapsed time is 21.619996 seconds. % without preallocation

Elapsed time is 0.464255 seconds. % with preallocation