RSEIS (version 1.0-9)

butfilt: Butterworth filter

Description

design and apply butterworth low/high/band pass filters.

Usage

butfilt(a, fl, fh, deltat, type, proto)

Arguments

a

vector signal

fl

low frequency cut-off

fh

high frequency cut-off

deltat

sample rate, s

type

type of filter, one of c("LP", "HP","BP" ,"BR" )

proto

prototype, c("BU", "BE" , "C1" ,"C2")

Value

• filtered time series

Details

LP{ for low pass } HP{ for high pass } BP{ for band pass } BR{ for band reject } BU{ for Butterworth } BE{ for Bessel } C1{ for Chebyshev type 1 } C2{ for Chebyshev type 2 }

Examples

data(CE1)

ts1 = CE1$y
zz = butfilt(ts1, 1, 15,  CE1$dt, "LP" ,  "BU")