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.
test.dataCT(type = "ppoly", n = 512, signal = 1, rsnr = 7, plotfn = FALSE)A list with the following components:
The points at which the test function is evaluated.
The values taken by the test function.
The simulated data set.
The type of function generated, identical to the input parameter type.
The root signal-to-noise ratio of the simulated data set, identical to the input parameter rsnr.
Test function to be computed. Available types are "ppoly" (piecewise polynomial), "blocks", "bumps", "heavi" (heavisine), and "doppler".
Number of equally spaced data points on which the function is evaluated.
Scaling parameter; the function will be scaled so that the standard deviation of the data points takes this value.
Root signal-to-noise ratio. Specifies the ratio of the standard deviation of the function to the standard deviation of the simulated errors.
If plotfn=TRUE, then the test function and the simulated data set are plotted
If plotfn=T, the test function and data set are plotted.
Part of the CThresh addon to WaveThresh. Copyright Stuart Barber and Guy Nason 2004.
Stuart Barber