Columns with at least one zero element

2014 6 16
3 个回答
回答已采纳
更新时间：2014 6 16
5 次查看（30 天）

0 个投票

Hi,
If I have a matrix with random dimension mxn , how can I detect a column which have at least one zero element?
Thank you

请先登录，再回答此问题。

 采纳的回答

Mischa Kim
Mischa Kim 2014-6-16
编辑：Mischa Kim 2014-6-16

0 个投票

Anya, you could use
A = [1 2 3 0 8; 5 0 1 2 2];
col = find(sum(A==0))
col =
2 4
col shows the columns which have at least one zero.

1 个评论
显示 -1更早的评论 隐藏 -1更早的评论

dpb
dpb 2014-6-16
Just for comparison...
>> A = [1 2 3 0 8; 5 0 1 2 2];
>> (sum(A==0))
ans =
0 1 0 1 0
>> all(A)
ans =
1 0 1 0 1
>> ~all(A)
ans =
0 1 0 1 0
>>

请先登录，再进行评论。

更多回答（2 个）

Jos (10584)
Jos (10584) 2014-6-16

1 个投票

Let M be your mxm matrix:
tf = any(M==0,1) % true for columns with at least 1 zero
C = M(:,~tf) % columns with no zeros

2 个评论
显示 无 隐藏 无

Anya
Anya 2014-6-16
This answer also works ! thx guys
dpb
dpb 2014-6-16
NB:
any(M==0) --> identically equal to ~all(M). One rarely (if ever) needs to expressly test for zero.
See the doc for each for details...

请先登录，再进行评论。

类别

在 帮助中心 和 File Exchange 中查找有关 Operating on Diagonal 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