# latc2tf

Convert lattice filter coefficients to transfer function form

## Syntax

``[b,a] = latc2tf(k,v)``
``[b,a] = latc2tf(k,iiroption)``
``b = latc2tf(k,firoption)``

## Description

````[b,a] = latc2tf(k,v)` returns the transfer function coefficients `b` and `a` corresponding to the IIR lattice-ladder filter specified by lattice coefficients `k` and ladder coefficients `v`.```
````[b,a] = latc2tf(k,iiroption)` specifies the option to generate an all-pole IIR filter transfer function or an allpass IIR filter transfer function.```

example

````b = latc2tf(k,firoption)` specifies the option to generate a minimum-phase FIR filter, a maximum-phase FIR filter, or a general FIR filter.```

## Examples

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Convert lattice coefficients to transfer function form. Specify the filter option as `"max"` to generate a maximum-phase FIR filter.

```k = [1/6 1/1.4]; b = latc2tf(k,"max")```
```b = 1×3 0.7143 0.2857 1.0000 ```

Confirm that the generated filter is maximum-phase.

`ismaxphase(b)`
```ans = logical 1 ```

## Input Arguments

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Lattice coefficients, specified as a vector.

Data Types: `single` | `double`

Ladder coefficients, specified as a vector.

Data Types: `single` | `double`

IIR filter option, specified as `"allpole"` or `"allpass"`. To obtain an all-pole filter transfer function from the associated all-pole IIR lattice filter coefficients `k`, specify `iiroption` as `"allpole"`. To obtain an allpass filter transfer function from the associated allpass IIR lattice filter coefficients `k`, specify `iiroption` as `"allpass"`.

Data Types: `char` | `string`

FIR filter option, specified as one of these:

• `"min"` — Obtain a minimum-phase FIR filter from the associated minimum-phase FIR lattice filter coefficients `k`.

• `"max"` — Obtain a maximum-phase FIR filter from the associated maximum-phase FIR lattice filter coefficients `k`.

• `"FIR"` — Obtain a general FIR filter from the associated lattice filter coefficients `k`. This option is equivalent to not specifying `iiroption` or `firoption`.

Data Types: `char` | `string`

## Output Arguments

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Transfer function coefficients, returned as vectors.

## Version History

Introduced before R2006a