What is the first and second drevitive of the unit step signal?

Code 200×(x>=0) to get unit step with amplitude equal to 200 ,and the first drevitive will be impulse as 200×(x==0),so I don't know if used correct code or not also if that okay how can implement the second drevitive of the unit step signal?

Answer 1

[Star Strider]

Do the experiment —

syms t 
u(t) = heaviside(t)

u(t) = 

dudt = diff(u)

dudt(t) = 

d2udu2 = diff(dudt)

d2udu2(t) = 

.

[Mohammed Yakoob]

Thank you for your reply dear friend!! My problem with haviside is how can implement this in for loop because I tested them but I get in error / xr(k+1)= haviside (t(k+1)) : this will be ok but when I use xr.dot(k+1)=diff(xr) : the error said unable to perform assignment because the left and right side have a different number of elements)

[Star Strider]

It would be helpful to see the relevant parts of your code. I do not understand the problem you are having.

Answer 2

[Mohammed Yakoob]

I'm so sorry to bother you again!! I tried to get good results by using this code S=200*heaviside(n); %to get unit step with 200 as implitude value. Then s.dot = diff(s) ; Finally s.ddot= diff(s.dot) And by using for loop have got samples of s, s.dot, and s.ddot!! The first drevitive was impulse with implitude 100 and the second drevitive also impulse but with - 100 is it okay or not?