test.data {waveband} | R Documentation

## Test functions for wavelet regression and thresholding

### Description

This function evaluates the "blocks", "bumps", "heavisine" and "doppler" test functions of Donoho & Johnstone (1994b) and the piecewise polynomial test function of Nason & Silverman (1994). The function also generates data sets consisting of the specified function plus uncorrelated normally distributed errors.

### Usage

    test.data(type = "ppoly", n = 512, signal = 1, rsnr = 7, plotfn = FALSE)

### Arguments

`type` | Test function to be computed. Available types are "ppoly" (piecewise polynomial), "blocks", "bumps", "heavi" (heavisine), and "doppler".
`n` | Number of equally spaced data points on which the function is evaluated.
`signal` | Scaling parameter; the function will be scaled so that the standard deviation of the data points takes this value.
`rsnr` | Root signal-to-noise ratio. Specifies the ratio of the standard deviation of the function to the standard deviation of the simulated errors.
`plotfn` | If `plotfn=TRUE`, then the test function and the simulated data set are plotted.

### Value

A list with the following components:

`x` | The points at which the test function is evaluated.
`y` | The values taken by the test function.
`ynoise` | The simulated data set.
`type` | The type of function generated, identical to the input parameter type .
`rsnr` | The root signal-to-noise ratio of the simulated data set, identical to the input parameter rsnr .

### SIDE EFFECTS

If `plotfn=TRUE`, the test function and data set are plotted.

[Package waveband version 4.0-2 Index]