how to vectorized a nested for loop?

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mohammed
mohammed on 13 Feb 2014
Commented: Jung Soo Park on 21 Feb 2018
i have two for loop and i want to vectorized it . i try a lot to do it but i cannot do it. this is the simple version is let
Mat = zeros(10)
for i = 1:10
for j = 1:10
Mat(i,j) = exp((i.^5) + j.^2);
end
end
Thanks.......

Answers (1)

Jan Orwat
Jan Orwat on 13 Feb 2014
Edited: Jan Orwat on 14 Feb 2014
Hello Mohammed, there are many ways to vectorize your loops. Check out those examples:
1.
[r,c]=meshgrid(1:10,1:10);
Mat=exp(c.^5+r.^2);
check function meshgrid in help to how it works (type doc meshgrid in commmand window)
2.
Mat=bsxfun(@(A,B)exp(A.^5+B.^2),(1:10)',1:10);
check bsxfun and function_handle
  • Also, please consider the fact that in your example, and in proposed vectorizations in matrix Mat columns from 4 to 10 have values equal to infinity due to maximum capacity of data precision.
  4 Comments
Jan Orwat
Jan Orwat on 14 Feb 2014
Thanks Mohammed, I've updated the answer. Now it is correct.
Jung Soo Park
Jung Soo Park on 21 Feb 2018
there are two minor errors on mohammed's reply dated 14feb2014. a=zeros(10,10) and isequal(a,Mat1)

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