Replace elements of sparse matrix from a full matrix.

7 次查看（过去 30 天）
KSSV
KSSV 2016-3-4
评论： Walter Roberson 2016-3-5
Dear Experts
I have a huge matrix, M with zeros. I am converting M into sparse using sparse(M). After, I want to replace few positions (idx) of M from other matrix, N. I am using the following: M(idx) = N(idx). But, this is very very slow. Also MATLAB warns: This sparse indexing expression is slow. How I can do the above task?
Thanks in advance.

请先登录，再回答此问题。

回答（1 个）

Jos (10584)
Jos (10584) 2016-3-4
What don't you replace the elements before converting it?
  8 个评论
显示 6更早的评论
KSSV
KSSV 2016-3-5
Actually my original matrix has zeros and I want to fill these zeros with numbers later...
Walter Roberson
Walter Roberson 2016-3-5
Then spalloc() would be appropriate. If you create a matrix without using it or equivalent then you end up doing a lot of sparse reallocations as you add in new values.

请先登录，再进行评论。

类别

在 Help Center 和 File Exchange 中查找有关 Sparse Matrices 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