Symbolic Math Toolbox™

iztrans - 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 = f(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
= n2ⁿ	`syms z` `f = 2z/(z-2)^2` `iztrans(f)` returns `2^n + 2^n(n - 1)`
= –1^k	`syms n` `g = n(n+1)/(n^2+2n+1)` `iztrans(g)` returns `(-1)^k`
= a^k if a ≠ 0	`syms z a k` `f = z/(z-a)` `simplify(iztrans(f,k))` returns `piecewise([a = 0, kroneckerDelta(k, 0)], [a <> 0, a^k])`

Inverse Z-Transform

MATLAB Operation