example.1 {wavethresh} | R Documentation

## Compute and return piecewise polynomial coordinates.

### Description

This function computes and returns the coordinates of the piecewise polynomial described by Nason and Silverman, 1994. This function is a useful test function for evaluating wavelet shrinkage methodology as it contains smooth parts, a discontinuity and it is periodic.

### Usage

    example.1()

### Details

This function computes and returns the x and y coordinates of the piecewise polynomial function described in Nason and Silverman, 1994. The formula for the piecewise polynomial (which is piecewise cubic) is given in Nason and Silverman, 1994 and is

(To be completed)

The piecewise polynomial returned is a discrete sample on 512 equally spaced points between 0 and 1 (including 0 but excluding 1).

### Value

A list with two components:

`x` | a vector of length 512 containing the ordered x ordinates of the piecewise polynomial.
`y` | a vector of length 512 containing the corresponding y ordinates of the piecewise polynomial.

### RELEASE

Version 3.5.3 Copyright Guy Nason 1994

### Examples

    #
    # Generate the piecewise polynomial
    #
    #test.data <- example.1()$y
    #ts.plot(test.data)

[Package wavethresh version 4.0-2 Index]