清空筛选条件
清空筛选条件

Finding location of change of signs of a matrix's elements

17 次查看（过去 30 天）
Volkan Yangin
Volkan Yangin 2017-2-18
评论： MA-Winlab 2019-4-7
Hi everbody, I have a matrix like this:
A=[0 0 0 0.33 0.33 0.33 0 0 0 -0.33 -0.33 -0.33 0 0 0];
How can i find location of change of signs? I get an error while using find and diff command. I think, i have made a mistake because of the < and > symbols. May you help me? Thanks.

请先登录，再回答此问题。

采纳的回答

Walter Roberson
Walter Roberson 2017-2-18
find(diff(sign(A)))+1
to return the locations of the beginning of the new sign.
Note that this includes changing to 0, as 0 has a different sign than positive numbers or negative numbers.
  3 个评论
显示 1更早的评论
MA-Winlab
MA-Winlab 2019-4-6
@Roberson, I tried your approach for finding the locations of change from 0 to 1 and from 1 to 0, but they are in one array.
So, if I have this array and want to find the locations of change from 1 to 0 (returned in an array) and the locations of change from 1 to 0 (returned in a SEPRATE array), how can I modify this line?
Thank you
A=[0 0 0 1 1 1 0 0 0 1 1 1 0 0 0];
MA-Winlab
MA-Winlab 2019-4-7
Update
I figured out how to do that (in my case, the vector of 0s and 1s has an even number):
OpenClose = find(diff(sign(A))) + 1;
OneToZero = OpenClose(1:2:end)
ZeroToOne = OpenClose(2:2:end)

请先登录，再进行评论。

更多回答（0 个）

类别

在 Help Center 和 File Exchange 中查找有关 Creating and Concatenating 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