Finding the length of square function

Hello, I'm using the square function. I want to find the length of it based on my limits. How can I do that since the square root is discontinues. Regards, Dimo

[John D'Errico]

Be far more clear about what you are trying to do. You want to find the length of a function? Are you asking to compute the arc length? Next, of what function? Be explicit, else we will spend time showing you how to solve the wrong problem.

[Dimo Iordanov]

I am sorry. I'm using this code for square function.

t=linspace(0,20,100);
X=3*square(2*pi*t/10)
plot(X,t)

I want to check how long the plot for that function is. I'm checking different patterns and seeing their distance.

[Rik]

Did you try to google how to calculate the arc length of a function in Matlab?

[Dimo Iordanov]

Yes, I did, and found the length of a sine function that I did before. I can use the same principle for finding a square function, but I think that it is going to get too messy. This is why I was wondering if anyone had any easier way of doing it. By messy I mean that the square functions are actually two functions that are activating by different values, and I believe I can solve it with a loop, by calculating each section of the wave, but I was wondering if there isn't a simpler way.

Regards,

Dimo

Answer 1

[Rik]

In general you can approximate the arc length by measuring the distances between the points and adding them.

t=linspace(0,20,100);
X=3*square(2*pi*t/10);
sum(hypot(diff(t),diff(X)))

Just a side note: I found this answer by John D'Errico as the 5th result when I googled 'arc length Matlab' detailing several methods to calculate the arc length. I suggest you take a look there as well.

Answer 2

[Rafael Hernandez-Walls]

t2=t(find(diff(X)>0));
t1=t(find(diff(X)<0));
long_time=t2(2)-t1(2)