iztrans (Symbolic Math Toolbox)

Inverse z-transform.

Syntax

f = iztrans(F)
f = iztrans(F,k)
f = iztrans(F,w,k)

Description

f = iztrans(F) is the inverse z-transform of the scalar symbolic object F with default independent variable z. The default return is a function of n:

where R is a positive number chosen so that the function F(z) is analytic on and outside the circle |z| = R

If F = F(n), iztrans returns a function of k:

f = iztrans(F,k) makes f a function of k instead of the default n. Here k is a scalar symbolic object.

f = iztrans(F,w,k) takes F to be a function of w instead of the default findsym(F) and returns a function of k:

Examples

Inverse Z-Transform
MATLAB Operation

f = 2*z/(z-2)^2

iztrans(f)
returns

2^n*n

g = n*(n+1)/(n^2+2*n+1)

iztrans(g)
returns

(-1)^k

f = z/(z-a)

iztrans(f,k)
returns

a^k

f = x*(x-exp(z))/
(x^2-2*x*exp(z)+exp(2*z))

iztrans(f,x,k)
returns
exp(z)^k

Inverse Z-Transform	MATLAB Operation
	`f = 2z/(z-2)^2` `iztrans(f)` returns 2^nn
	`g = n(n+1)/(n^2+2n+1)` `iztrans(g)` returns `(-1)^k`
	`f = z/(z-a)` `iztrans(f,k)` returns `a^k`
	`f = x(x-exp(z))/` `(x^2-2xexp(z)+exp(2z))` `iztrans(f,x,k)` returns exp(z)^k