How to improve the code for vector calculation

Question

krishnamurthy 2013-6-13

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/78907-how-to-improve-the-code-for-vector-calculation

在 MATLAB Online 中打开

clear all

clc

NG=3;

B_area=rand(12,3);

P=rand(1,12)

P1=P(1:3);P2=P(4:6);P3=P(7:9);P4=P(10:12);

B_area1=B_area((1:3),:);

B_area2=B_area((4:6),:);

B_area3=B_area((7:9),:);

B_area4=B_area((10:12),:);

for i=1:NG

     for j=1:NG  
        PL_area1(j)=P1(i).*B_area1(i,j).*P1(j);
        PL_area2(j)=P2(i).*B_area2(i,j).*P2(j);
        PL_area3(j)=P3(i).*B_area3(i,j).*P3(j);
        PL_area4(j)=P4(i).*B_area4(i,j).*P4(j);
    end
    eval(['PL_area1' num2str(i) '=(PL_area1)']);
    eval(['PL_area2' num2str(i) '=(PL_area2)']);
    eval(['PL_area3' num2str(i) '=(PL_area3)']);
    eval(['PL_area4' num2str(i) '=(PL_area4)']);

end

PL_area1=sum(PL_area11(:,:)+PL_area12(:,:)+PL_area13(:,:));

PL_area2=sum(PL_area21(:,:)+PL_area22(:,:)+PL_area23(:,:));

PL_area3=sum(PL_area31(:,:)+PL_area32(:,:)+PL_area33(:,:));

PL_area4=sum(PL_area41(:,:)+PL_area42(:,:)+PL_area43(:,:));

PL=[PL_area1 PL_area2 PL_area3 PL_area4]

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Andrei Bobrov 2013-6-13

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/78907-how-to-improve-the-code-for-vector-calculation#answer_88656

在 MATLAB Online 中打开

B = rand(12,3);
P = rand(1,12);
Ba = permute(reshape(B,3,4,[]),[1 3 2]);
Pn = reshape(P,3,1,[]);
Pa = bsxfun(@times,Pn,reshape(Pn,1,3,[])).*Ba;
PL = sum(reshape(Pa,[],4));