清空筛选条件
清空筛选条件

how to use vectorized language or any other methods to replace the following code, in order to make the computation faster

2 次查看（过去 30 天）
Jason
Jason 2016-1-12
评论： Jason 2016-1-13
following are my current code:
if true
% code
tic;
S = size(P,1);
Q2 = -permute(P,[2 3 1]);
for i = 1:S
Q2(i,:,i) = Q2(i,:,i) + 1;
end
Q2 = reshape(Q2,S,[]);
toc
end
P is the transition probability matrix,
if true
% code
P(:,:,1)=[3/4 1/4;3/4 1/4];
P(:,:,2)=[1/4 3/4;1/4 3/4];
end
My problem is that when the dimension of P is larger than 8000*8000*8,the current computation will be very slow.Is there anyone who know how to optimize the current code? Thank you in advance！

请先登录，再回答此问题。

采纳的回答

jgg
jgg 2016-1-12
I think this should work. Replace your for loop with:
i = [1:S]
Q2(i,:,i) = Q2(i,:,i) + 1;
This works on the test case you posed, as far as I can tell, so I think it should work on your much bigger data. Let me know!

更多回答（0 个）

类别

在 Help Center 和 File Exchange 中查找有关 Loops and Conditional Statements 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by