# filt

Constructs a transfer function model in DSP format.

## Syntax

SYS = filt(NUM, DEN)

SYS = filt(NUM, DEN, Ts)

## Inputs

NUM
A scalar or a row vector (numerator).
DEN
A scalar or a row vector (denominator).
Ts
Sampling time Ts (in seconds).
Ts = -1 leaves the sampling time unspecified.
Default is Ts = 0.

## Outputs

SYS
Transfer function model in variable z-1.

## Examples

Transfer function model for a discrete time system:
num = [3 4];
den = [3 1 5];
Ts = 0.2;
sys = filt(num, den, Ts)
Transfer function for input 1, output 1

3 + 4 z^-1
-----------------
3 + z^-1 + 5 z^-2

Sampling Time: 0.2 s

## Comments

Adding the Ts parameter allows you to define the discrete-time transfer function.

When NUM and DEN have different lengths, the shorter vector is treated as having trailing zeros. See tf for comparison.