sparse function is intrisically slow?

9 次查看（过去 30 天）

Jiangtao Lu 2020-5-7

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/523719-sparse-function-is-intrisically-slow

评论： Yingzhi Liu 2022-3-19

I am building the sparse matrix using the function sparse(I,J,V,N,N)

I, J and V are already a column vector. I checked previous questions, it seems already being the best way. But, it takes extreamely long time if the size goes to 1E5.

Any way out? Thanks!

14 个评论
显示 12更早的评论隐藏 12更早的评论

James Tursa 2020-5-12

OK. Are the values in the double vector stored in the same memory order as the sparse matrix columns? Can you give a small example of your indexing and values vector? I'm asking all of these questions to see if a mex routine could work for you.

Jiangtao Lu 2020-5-12

编辑：Jiangtao Lu 2020-5-12

在 MATLAB Online 中打开

matlab.mat

I am not clear to that question. The calculation is like:

work.jacValueIndex = numC*(work.g(work.J)-1)+work.I;
jacValue = df(work.jacValueIndex)./dc(work.J);
jac = sparse(work.I,work.J,jacValue,numC,numC);

I attached an example of work and jacValue

请先登录，再进行评论。

请先登录，再回答此问题。

回答（1 个）

Robert 2020-12-24

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/523719-sparse-function-is-intrisically-slow#answer_583877

I was able to speed my sparse matrix build for very large problems by using sparse2.m (mexFunction) from SuiteSparse.

1 个评论
显示 -1更早的评论隐藏 -1更早的评论

Yingzhi Liu 2022-3-19

I downloaded SuiteSparse, but I don't konw how sould I do to use sparse2.m in matlab. Can you help me list the steps after downloaded SuiteSparse? Thanks.

请先登录，再进行评论。

请先登录，再回答此问题。