R: Calls C code to threshold wd class object.

Cthreshold {wavethresh} | R Documentation

## Calls C code to threshold wd class object.

### Description

A routine that calls a C code function to do thresholding. This is really a test routine to call a C thresholding function (Cthreshold) and the user is advised to use the R based generic thresholding function `threshold` and/or its methods as they contain a wider range of thresholding options.

### Usage

    Cthreshold(wd, thresh.type = "soft", value = 0, levels = 3:(nlevelsWT(wd) - 1))

### Arguments

`wd` | The wavelet object that you wish to threshold.
`thresh.type` | The type of thresholding. This can be "soft" or "hard". See `threshold` and methods for further details.
`value` | The threshold value that you want to be used (e.g. for hard thresholding wavelet coefficients whose absolute value is less than
`levels` | The resolution levels that you wish to compute the threshold on and apply the threshold to.

### Details

For general use it is recommended to use the `threshold` functions as they have a wider variety of options and also work for more complex varieties of wavelet transforms (i.e. non-decimated, complex-valued, etc). However, in the right, limited, situation this function can be useful. This function directly calls the C thresholding function Cthreshold(). The C function is used by routines that operate on behalf of the function that carries out two-fold cross validation in C (`CWCV`) which is also accessible using the `policy="cv"` option too `threshold.wd`

This function can be used by the user. It might be a bit faster than `threshold.wd` but mostly because it is simpler and does less checking than `threshold.wd`.

### Value

A `wd.object` class object, but containing thresholded coefficients.

### Author(s)

G P Nason

### See Also

`threshold`

### Examples

    #
    # See copious examples in the help to threshold.wd
    #

[Package wavethresh version 4.6.8 Index]