# zp2tf

Zero-pole to transfer function conversion.

## Syntax

[NUM, DEN] = zp2tf(Z, P, K)

## Inputs

`Z`- Zero locations, stored by column for each system output.
`P`- Pole locations, stored in a column vector.
`K`- System gain factor(s), stored as a scalar or row vector.

## Outputs

- NUM
- Numerator coefficients, stored by row for each system output.
- DEN
- Denominator coefficients, stored in a row vector.

## Example

```
num = [3 2];
den = [5 2 3];
[z, p, k] = tf2zp(num, den);
[num, den] = zp2tf(z, p, k)
```

```
num = [Matrix] 1 x 2
0.60000 0.40000
den = [Matrix] 1 x 3
1.00000 0.40000 0.60000
Ts = 0
```

## Comments

The zeros and poles must be either real or complex conjugate pairs.

The vectors of NUM and DEN are in descending powers of s.