R: Compute and return simulated chirp function.

simchirp {wavethresh} | R Documentation

## 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.

### 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.

### 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

### Author(s)

G P Nason

### Examples

    #
    # Generate the chirp
    #
    test.data <- simchirp()$y
    ## Not run: ts.plot(test.data)

[Package wavethresh version 4.6.8 Index]