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test.data
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 = F)
REQUIRED ARGUMENTS
None.
OPTIONAL 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=T, 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=T, the test function and data set are plotted.
RELEASE
3.9.7