find where number changes in a matrix

3 次查看（过去 30 天）
joseph Frank
joseph Frank 2013-3-23
I have a matrix of +1 and -1 values. I want to find where the number flips from 1 to -1 or vice versa where the change is a change from column to column.
X=[...
1 1 1 1;
1 -1 1 1;
1 1 1 -1;
1 1 1 1]
the answer should be [2,2],[2,3]and [3,4]. I tried
find(diff(X)==2);
find(diff(X)==-2);
Any help is appreciated

请先登录，再回答此问题。

采纳的回答

Cedric
Cedric 2013-3-23
>> [r,c] = find(diff(X,1,2)) ;
>> loc = [r, c+1]
loc =
2 2
2 3
3 4

更多回答（1 个）

the cyclist
the cyclist 2013-3-23
One way:
[i j] = find(abs([zeros(4,1),diff(X,[],2)])==2)

类别

在 Help Center 和 File Exchange 中查找有关 Loops and Conditional Statements 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