# filter

1-D digital filter of `fi`

objects

## Description

filters the data in the fixed-point vector `y`

= filter(`b`

,1,`x`

)`x`

using the filter described
by the fixed-point vector `b`

. The function returns the filtered data in
the output `fi`

object `y`

.

`filter`

always operates along the first non-singleton dimension.
Thus, the filter operates along the first dimension for column vectors and nontrivial
matrices and along the second dimension for row vectors.

## Examples

## Input Arguments

## Output Arguments

## Tips

The

`filter`

function only supports FIR filters. In the general filter representation*b*/*a*, the denominator*a*of an FIR filter is the scalar 1, which is the second input of this function.The

`numerictype`

of`b`

can be different than the`numerictype`

of`x`

.If you want to specify initial conditions but do not know what

`numerictype`

to use, first try filtering your data without initial conditions. You can do so by specifying`[]`

for the input`zi`

. After performing the filtering operation, you have the`numerictype`

of`y`

and`zf`

(if requested). Because the`numerictype`

of`zi`

must match that of`y`

and`zf`

, you now know the`numerictype`

to use for the initial conditions.

## Algorithms

## Extended Capabilities

## Version History

**Introduced in R2010a**