Calculate high and low length of given square wave?

warning matlab beginner here :-/

I would like to calculate the high and low pulselength from a real signal, if it is over 10 it is high under 10 it is low. Signal consists of 2002x2 numbers, time and voltage from a light bar...

If i import it with matlab i get 2 seperate double variables, voltage and time as "2002x1 double".

Now to segment the high pulse:

highSignals = signal > 10

Now i can count the high numbers (logic 1) and if i knwo the time distance from before i have the length.

Like: NumberofOnes=50 HighTime=dt*NumberofOnes

Can anyone give me a tip which function does that easyier or more structurised?

Answer 1

[Ameer Hamza]

If you have Image Processing Toolbox, then one option is to use regionprops() to find the length of all the high areas and then average them to get a better estimate of highTime.

dt = mean(diff(second)); % sampling time
highRegions = regionprops(Volt>10, 'Area');
averageNumberofOnes = mean([highRegions.Area]);
highTime = averageNumberofOnes*dt;

[Image Analyst]

Moes, if you want all the lengths of the valid sections individually you can do

allAreas = [highRegions.Area];
allTimes = dt * allAreas;

[MoeIsKing]

yep thats the one :-P

i got the Image Processing Toolbox somehow ^^ nice thanks