Efficient slicing of cell array?

2015 3 20
1 个回答
回答已采纳
更新时间：2015 3 20
5 次查看（30 天）

0 个投票

I have a cell array of the form:
c =
[1x100 double]
[2x150 double]
[3x200 double]
And I would like to create a 6x50 matrix consisting of all rows and the first 50 columns of each constituent matrix. Is there an efficient way to do this?

请先登录，再回答此问题。

 采纳的回答

Andrei Bobrov
Andrei Bobrov 2015-3-20

1 个投票

variant
cell2mat(cellfun(@(x)x(:,1:50),C,'un',0));

1 个评论
显示 -1更早的评论 隐藏 -1更早的评论

EGTork
EGTork 2015-3-20
编辑：EGTork 2015-3-20
Thanks, Andrei. For reference, I compared this cell array approach against directly indexing a matrix to create a submatrix. The cell array solution took about 5X as long, which is not bad considering the extra flexibility provided by cell arrays.
Specifically, I took a cell array containing five 10x100,000 matrices, and used your approach to generate a 50x75,000 submatrix. I compared this to directly indexing into a 50x100,000 matrix to create a 50x75,000 submatrix. For matrices of this size, there was a 5X penalty for using cell arrays instead of a matrix. For smaller matrices, the penalty was somewhat higher (~10X).

请先登录，再进行评论。

更多回答（0 个）

类别

在 帮助中心 和 File Exchange 中查找有关 Matrix Indexing 的更多信息

产品

标签

Community Treasure Hunt

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

Start Hunting!

Translated by