How can I vectorize these for loops?
显示 更早的评论
Newbie here. I was wondering if there was a way to vectorize these for loops, or simply to change it to make it faster? Any help would be appreciated. Thank you!
m = zeros(50);
d = zeros(50);
for i = 1:size(m,1)
for n = 1:size(m,2)
try d(i,n) = sum(m(i-1:i+1,n-1:2:n+1),'all') + sum(m(i-1:2:i+1,n),'all');
catch, continue
end
end
end
What it does is scan the matrix positions immediately surrounding each matrix position being looped through and sums the values. It doesn't work at the edges or the corners, which is what the try, catch statement is for. Thanks again.
2 个评论
Stephen23
2020-5-28
x = [1,1,1;1,0,1;1,1,1];
d = conv2(m,x,'same');
Budhvin Jayasinghe
2020-5-28
采纳的回答
Mohammad Sami
2020-5-28
What you are trying to do is 2D convolution. There is a function conv2 that will allow you to do this.
m = ones(50);
filter = ones(3);
filter(2,2) = 0;
% 3x3 filter with excluding the center.
d = conv2(m,filter,'same');
更多回答（0 个）
类别
在 帮助中心 和 File Exchange 中查找有关 Programming 的更多信息
产品
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!
Translated by 
