Select values from a signal

Hi, would like to find the way to identity an specific value from a signal (example on image 1).

This is an example of a signal after excute RMS.

At this moment, I need to take EMG values (y) from an specific moment of time (x).

For example, if I would like to take value from x point 1245, or 4567, How culd I code this?

Thank You

Answer 1

[Image Analyst]

Not sure if your x axis are real world units, or simply indexes. If they're indexes, simply refer to them:

y1 = y(1245);
y2 = y(4567);

If they're not indexes, but real world values, then you need to find the index that is closest to your desired x value. Once you have that index, you can extract the y value you want.

[~, index] = min(abs(x - 1245));
y1 = y(index);

[Julio Martín]

Hi, they real values (miliseconds), don't know how to find the index

Thank you

[Image Analyst]

Why do you not know how to find the index where x is closest to 1245? I specifically showed you how in my last comment. Again:

[~, index] = min(abs(x - 1245));
y1 = y(index);

[Julio Martín]

It’s true,, really works Thank you very much