How do you find the max within a specified window?

so i have a plot where i want to find the maximum point within that plot. There is a set window or parameter that i want to find the maximum point. How do I find the x and y value of the point with the specified windows? thank you!

Answer 1

[Image Analyst]

To find the max(es) within one specified window location:

[maxYValue maxXIndex] = max(signal(element1:element2));

where element1 and element2 say what element (index) you want to start and stop your window at.

Or, if you have the Image Processing Toolbox and you want to find the maximum in every window as it slides along your signal, then you can use imdilate().

allMaxes = imdilate(signal(element1:element2), ones(1, windowWidth));

[Leah]

thank you!!

[Alan Keenan]

What if the X axis are time stamps? How do you convert the time stamps to array indices?

[Image Analyst]

@Alan Keenan, not sure what you mean. You can still use max() on times, maybe not all styles of times but certainly serial date vectors. Post your data in a new question if you still have questions.

[Alan Keenan]

@ Image Analyst, the x axis is time from 0 to 6us. I want to use max(data) within two points in time, say between 2.0e-6 and 2.2e-6, however the expected syntax is element idices rather than time points. I will open a new question and thanks for your comments.

Answer 2

[Steven Lord]

Depending on whether you want the windows to overlap or not, the movmax function (which did not exist when the question was asked) may be of use as well.