wavethresh (version 4.6.9)

simchirp: Compute and return simulated chirp function.

Description

This function computes and returns the coordinates of the reflected simulated chirp function described in Nason and Silverman, 1995. This function is a useful test function for evaluating wavelet shrinkage and time-scale analysis methodology as its frequency changes over time.

Usage

simchirp(n=1024)

Arguments

n

The number of ordinates from which to sample the chirp signal.

Value

A list with two components:

x

a vector of length n containing the ordered x ordinates of the chirp from -1 to 1.

y

a vector of length n containing the corresponding y ordinates of the chirp.

RELEASE

Version 3.5.3 Copyright Guy Nason 1994

Details

This function computes and returns the x and y coordinates of the reflected chirp function described in Nason and Silverman, 1995.

The formula for the reflected simulated chirp is *formula*

The chirp returned is a discrete sample on n equally spaced points between -1 and 1.

Examples

# NOT RUN {
#
# Generate the chirp
#
test.data <- simchirp()$y
# }
# NOT RUN {
ts.plot(test.data)
# }