fir1: FIR filter generation

Description Usage Arguments Value Author(s) References See Also Examples

View source: R/fir1.R

Description

FIR filter coefficients for a filter with the given order and frequency cutoff.

Usage

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fir1(n, w, type = c("low", "high", "stop", "pass", "DC-0", "DC-1"), 
     window = hamming(n + 1), scale = TRUE)

Arguments

n

order of the filter (1 less than the length of the filter)

w

band edges, strictly increasing vector in the range [0, 1], where 1 is the Nyquist frequency. A scalar for highpass or lowpass filters, a vector pair for bandpass or bandstop, or a vector for an alternating pass/stop filter.

type

character specifying filter type, one of "low" for a low-pass filter, "high" for a high-pass filter, "stop" for a stop-band (band-reject) filter, "pass" for a pass-band filter, "DC-0" for a bandpass as the first band of a multiband filter, or "DC-1" for a bandstop as the first band of a multiband filter.

window

smoothing window. The returned filter is the same shape as the smoothing window.

scale

whether to normalize or not. Use TRUE or 'scale' to set the magnitude of the center of the first passband to 1, and FALSE or 'noscale' to not normalize.

Value

The FIR filter coefficients, an array of length(n+1), of class Ma.

Author(s)

Original Octave version by Paul Kienzle, pkienzle@user.sf.net. Conversion to R by Tom Short.

References

https://en.wikipedia.org/wiki/Fir_filter

Octave Forge https://octave.sourceforge.io/

See Also

filter, Ma, fftfilt, fir2

Examples

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freqz(fir1(40, 0.3))
freqz(fir1(10, c(0.3, 0.5), "stop"))
freqz(fir1(10, c(0.3, 0.5), "pass"))

Example output

Attaching package: 'signal'

The following objects are masked from 'package:stats':

    filter, poly

signal documentation built on May 25, 2021, 9:06 a.m.

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