i have to implement a discrete time derivative. i am a beginner at matlab and need thorough assistance please.

Create a new MATLAB m-function of the form function y = num_derivative(u,T) and implement the discrete-time derivative (16). o The function must accept any column vector 𝑢 (=discrete-time input signal) of arbitrary length and a positive real number 𝑇 (=sampling time) as input arguments. o The function must generate a column vector 𝑦 of the same length as the input 𝑢 as output. The first value in 𝑦, which cannot be determined based on the available input samples 𝑢[𝑘], shall be set to zero.

(16) is u[𝑘] ≈ 𝑢[𝑘] − 𝑢[𝑘 − 1] /T

Answer 1

[Shreeya]

Hi @Abdelrhman Haggy

I understand that you want to implement the discrete time derivative using m-function in MATLAB. Given input arguments are u[k], a column vector input with initial value set to zero and T.

You can follow the following steps to construct the function:

• Prepend zero to u vector to enforce the initial condition.
• Iterate over the vector, starting from the second index using a for loop.
• Evaluate equation 16.
• Store the results in an output vector y.

Refer to the pseudo code for more details.

function y = discrete_time_derivative(u,T)
    y = zeros(size(u))
    u = [0;u]
    for i = 2:length(u)
        y(i) = (u(i)-u(i-1))/T
    end
end

Hope this helps!