How can i vectorize a matrix multiplication of higher dimension arrays?

5 ビュー (過去 30 日間)
Anthony Barone
Anthony Barone 2016 年 4 月 1 日
回答済み: Steven Lord 2020 年 9 月 17 日
I want to multiply a 6x6 matrix A and a 6x1 vector B at every grid point in a 3D earth model. Currently I am doing this:
for ix=1:length(x)
for iy=1:length(y)
for iz=1:length(z)
C(:,ix,iy,iz)=squeeze(A(:,:,ix,iy,iz))*squeeze(B(:,ix,iy,iz));
end
end
end
Is there a way to vectorize this? Currently this segment of nested loops is by far the slowest part of my code (almost 90% of the time taken every iteration is spent in this nested loop). Thanks!
  1 件のコメント
Anthony Barone
Anthony Barone 2016 年 4 月 1 日
I have found an answer, but I still wanted to post it incase anyone else has a similiar situation. I did this:
for n=1:6
C(n,:,:,:)=sum(squeeze(A(n,:,:,:,:)).*B);
end
For me, this method proved to be ~30x faster than my initial method.

サインインしてコメントする。

回答 (2 件)

Steven Lord
Steven Lord 2020 年 9 月 17 日
If you're using release R2020b or later, take a look at the pagemtimes function introduced in that release.

Matt J
Matt J 2016 年 4 月 1 日
Using mtimesx ( Download )
C=mtimesx( reshape(A,6,6,[]) , reshape(B,6,1,[]) );
C=reshape(C,size(B));

カテゴリ

Help Center および File ExchangeJust for fun についてさらに検索

製品

Community Treasure Hunt

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

Start Hunting!

Translated by