INVRft {RSEIS}

Inverse Fourier Transform

Description

Inverse Fourier Transform

Usage

INVRft(G, n, tstart, dt)

Arguments

G

Input fourier transform

n

length of time vector

tstart

time series starts at tstart

dt

Delta t, sample rate

Details

G is a vector spectrum evaluated at positive and negative frequencies as defined by makefreq. tstart, dt and n define the output time vector as described above.

g is the Inverse Fourier Transform of G scaled by dt. time shift theorem has been used to account for time not starting at t=0.

Value

g

truncate time vector to N points

f

frequencies

t

times

Author(s)

Jonathan M. Lees<jonathan.lees.edu>

See Also

makefreq, FRWDft, INSTresponse

Examples

zil  <-  rnorm(300)
fss  <-  FRWDft( zil, length(zil), 0, 0.004)   
INVRft(fss$G, length(zil), 0, 0.004)