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FIR or IIR lowpass filter

The `dsp.LowpassFilter`

object independently filters each channel of the
input over time using the given design specifications. You can set the
`FilterType`

property of `dsp.LowpassFilter`

to `'FIR'`

or `'IIR'`

to
implement the object as a FIR or IIR lowpass filter.

To filter each channel of your input:

Create the

`dsp.LowpassFilter`

object and set its properties.Call the object with arguments, as if it were a function.

To learn more about how System objects work, see What Are System Objects? (MATLAB).

`LPF = dsp.LowpassFilter`

`LPF = dsp.LowpassFilter(Name,Value)`

returns a minimum
order FIR lowpass filter, `LPF`

= dsp.LowpassFilter`LPF`

, with the default filter settings.
Calling the object with the default property settings filters the input data with a
passband frequency of `8`

kHz, a stopband frequency of
`12`

kHz, a passband ripple of `0.1`

dB, and a
stopband attenuation of `80`

dB.

returns a lowpass filter, with additional properties specified by one, or more
`LPF`

= dsp.LowpassFilter(`Name,Value`

)`Name,Value`

pair arguments. `Name`

is the
property name and `Value`

is the corresponding value.
`Name`

must appear inside single quotes (' '). You can specify
several name-value pair arguments in any order as
`Name1,Value1,...,NameN,ValueN`

.

**For versions earlier than R2016b, use the step
function to run the System object™ algorithm. The arguments to
step are the object you created, followed by
the arguments shown in this section.**

**For example, y = step(obj,x) and y = obj(x) perform equivalent operations.**

`y = LPF(x)`

To use an object function, specify the
System
object as the first input argument. For
example, to release system resources of a System
object named `obj`

, use
this syntax:

release(obj)

[1] Shpak, D.J., and A. Antoniou. "A generalized Remez method for the design of FIR
digital filters." *IEEE ^{®} Transactions on Circuits and Systems*. Vol. 37, Issue 2, Feb. 1990,
pp. 161–174.

[2] Selesnick, I.W., and C. S. Burrus. "Exchange algorithms that complement the
Parks-McClellan algorithm for linear-phase FIR filter design." *IEEE Transactions on Circuits and Systems*. Vol. 44, Issue 2, Feb. 1997,
pp. 137–143.