Find the threshold point in a matrix

2 次查看（过去 30 天）
MByk
MByk 2017-11-22
评论： MByk 2017-11-23
I have a 178x13 double matrix. In each column there is a point where each data value starts to stay same. I want to find them (row number). For example for the first column it is 70. I tried "find(diff(values(:,1)) == 0, 1, 'first')" but it is not working. How can I do this? Thanks for the help.

请先登录，再回答此问题。

采纳的回答

Image Analyst
Image Analyst 2017-11-22
You can have differences equal to zero that are not in the last stretch of zeros. Therefore you need to use findgroups() or regionprops() to find the first element of the last group of zeros. If you need a demo, attach your data in an mat file with the paper clip icon.
  3 个评论
显示 1更早的评论
Image Analyst
Image Analyst 2017-11-23
That's not a great example because all those columns go steady state at exactly the same row. This simple code will do it quickly:
data = importdata('myfile.txt')
[rows, columns] = size(data)
for col = 1 : columns
fprintf('Finding where column #%d equals %f . . . ', col, data(end, col));
steadyStateLocations(col) = find(data(:, col) ~= data(end, col), 1, 'last');
fprintf('it happens at row %d.\n', steadyStateLocations(col));
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 Numeric Types 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