Simplification of two for loops

Hi,

I would like to simplify the two for loop to accelerate my calculation time

Maybe, you have an idea how can I do it. My code draw inside the Matrix M(N,N) the circles with following function

M(i,j)=(1-sin((pi*rad)/(2*radius1)))*exp(w*rad).

So, I have:

M=zeros(N,N);
for i=1:N
  for j=1:N
    if  (i-i1)^2+(j-j1)^2  <  radius1^2
      radius = sqrt((i-i1)^2+(j-j1)^2);
      M(i,j)=(1-sin((pi*radius)/(2*radius1)))*exp(w*radius);
    end
  end
 end

Thank you in advance for any better suggestions!!!

Best regards,

Answer 1

[Bruno Luong]

i = (1:N)';
j = 1:N;
radius = sqrt((i-i1).^2+(j-j1).^2);
M = (1-sin((pi*radius)/(2*radius1))).*exp(w*radius);
M(radius>=radius1) = 0;