impulse response from transfer function in matlab

i have a transfer function given by

H(z)= 1-z^(-1)/1-z^(-1)+z^(-2)

how to find its impulse response h(n) in matlab what is the code for the same ?

Answer 1

[Star Strider]

This is how I would do it:

% H(z)= 1-z^(-1)/1-z^(-1)+z^(-2)
b = [1 -1];
a = [1 -1  1];

figure(1)
impz(b,a)

[pavan sunder]

Thanks bro. would you also kindly help me with plotting the poles and zeros of the same transfer function in Z plane..

[Star Strider]

Sure. Use the zplane function:

b = [1 -1];
a = [1 -1  1];

figure(2)
zplane(b,a)

[pavan sunder]

i tried this option but i did not get the plot;

[pavan sunder]

hey sorry bro.i got the plot. the mistake was was i had not entered figure command..anyways thanks ! :)

[Star Strider]

My pleasure.

MATLAB will plot in the available figure window, so to get two plots (the first using impz and the second using zplane), you have to specify two separate figures.

[M.Moksha laxmi]

In the same problem what should I do if I want to plot the step response?

[Star Strider]

@M.Moksha laxmi —

Use the stepz function

% H(z)= 1-z^(-1)/1-z^(-1)+z^(-2)
b = [1 -1];
a = [1 -1  1];

figure(1)
impz(b,a)

figure(2)
stepz(b,a)

.

Answer 2

[Abdul Jabbar]

z^-1 -4z^-2 -2z^-4 can any one tell me that how i can find the impulse response of this function?

[Petar Mostarac]

Is this a joke? :)

It is -1, -4 0 -2 and zeros to inf.

z^-1 is one sample delay, one step delay

Formarly, use basic knowladge to find H(z) in form H=b/a and then you can use:

h=impz(b,a, length_of_impulse_response)

In your question: b=[1 -4 0 -2] and a=[1 0 0 0]

If it is a joke, then is a good one :)

[Paul]

Actually, the solution with impz should have: b = [0 1 -4 0 -2]