# tf2latc

Convert transfer function filter coefficients to lattice filter form

## Syntax

``[k,v] = tf2latc(b,a)``
``[k,v] = tf2latc(b0,a)``
``k = tf2latc(1,a)``
``k = tf2latc(b)``
``k = tf2latc(b,phase)``

## Description

````[k,v] = tf2latc(b,a)` returns the lattice coefficients `k` and the ladder coefficients `v` for an IIR (ARMA) lattice-ladder filter, normalized by `a(1)`. The function errors if one or more of the lattice coefficients are exactly equal to 1.```
````[k,v] = tf2latc(b0,a)` returns the ladder coefficients where only the first element in `v` is nonzero. `b0` is a scalar.```

example

````k = tf2latc(1,a)` returns the lattice coefficients `k` for an IIR all-pole (AR) lattice filter.```
````k = tf2latc(b)` returns the lattice coefficients `k` for an FIR (MA) lattice filter, normalized by `b(1)`.```
````k = tf2latc(b,phase)` specifies the type of FIR (MA) lattice filter as minimum-phase or maximum-phase.```

## Examples

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Convert an all-pole IIR filter to lattice coefficients.

```a = [1 13/24 5/8 1/3]; k = tf2latc(1,a)```
```k = 3×1 0.2500 0.5000 0.3333 ```

## Input Arguments

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Transfer function coefficients, specified as vectors.

Data Types: `single` | `double`

Transfer function numerator coefficients, specified as a scalar.

Data Types: `single` | `double`

Type of FIR (MA) filter, specified as either `"max"` or `"min"`. For a maximum-phase filter, specify `phase` as `"max"`. For a minimum-phase filter, specify `phase` as `"min"`.

Data Types: `char` | `string`

## Output Arguments

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Lattice coefficients, returned as a vector.

Ladder coefficients, returned as a vector.

## Version History

Introduced before R2006a