Edge detection between position and neagtive

Hi guys, Im trying to do in matlab edge detection that when I have a change value between 1 to -1 or between -1 to 1 (ranges is -1<data<1) ) so will detect this crosses/sections between moving from positive to negative or from negative to positive!

any help how can I do that edge detector in matlab? thanks alot

Answer 1

[Image Analyst]

Is this what you're looking for:

% Create sample data in the range -1 to +1.
v = 2 * rand(1, 50) - 1
% Find out which ones of those are negative.
negativeIndexes = v < 0
% Find where it goes from above 0 to below 0
crossingIndexes = strfind(negativeIndexes, [0, 1])