Edge Detection without function

How to make edge detection manually / without Matlab function?

[Walter Roberson]

What operations are you permitted? For example in MATLAB, the == operator is a function.

Answer 1

[Luna]

Hello Fifit,

Signal should be a vertical vector. Value is a constant double. Index is the result which is a logical array where rising or falling edge occured.

Try this code:

signal = [10 10 5 5 2 2 2 5 5 8 8 5 5]'
value = 5;

This is for rising edge:

locations = (signal >= value);
diff_locations = [false ; diff(locations)];
index = (diff_locations ==1);

This is for falling edge:

locations = (signal <= value);
diff_locations = [false ; diff(locations)];
index = (diff_locations == 1);

[Holden Tranquillo]

Great method, thanks