TASC: Trinarization Across Multiple Scales

Description Usage Arguments Details Value See Also Examples

View source: R/TASC.R

Description

Trinarizes real-valued data using the multiscale TASC method.

Usage

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TASC(vect, 
	method = c("A","B"), 
	tau = 0.01, 
	numberOfSamples = 999, 
	sigma = seq(0.1, 20, by=.1),
	na.rm=FALSE,
	error = c("mean", "min"))

Arguments

method

Chooses the TASC method to use (see details), i.e. either "A" or "B".

vect

A real-valued vector of data to trinarize.

tau

This parameter adjusts the sensitivity and the specificity of the statistical testing procedure that rates the quality of the trinarization. Defaults to 0.01.

numberOfSamples

The number of samples for the bootstrap test. Defaults to 999.

sigma

If method="B", this specifies a vector of different sigma values for the convolutions with the Bessel function. Ignored for method="A".

na.rm

If set to TRUE, NA values are removed from the input. Otherwise, trinarization will fail in the presence of NA values.

error

Determines which error should be used for the data points between two thresholds, the "mean" error (default) to the thresholds or the "min" error.

Details

The two TASC methods can be subdivided into three steps:

Compute a series of step functions:

An initial step function is obtained by rearranging the original time series measurements in increasing order. Then, step functions with fewer discontinuities are calculated. TASC A calculates these step functions in such a way that each minimizes the Euclidean distance to the initial step function. TASC B obtains step functions from smoothened versions of the input function in a scale-space manner.

Find strongest discontinuities in each step function:

A strong discontinuity is a high jump size (derivative) in combination with a low approximation error. For TASC a pair of strongest discontinuities is determined.

Estimate location and variation of the strongest discontinuities:

Based on these estimates, data values can be excluded from further analyses.

Value

Returns an object of class TASCResult.

See Also

TrinarizationResult, TASCResult

Examples

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par(mfrow=c(2,1))
result <- TASC(iris[,"Petal.Width"], method="A", tau=0.15)
print(result)
plot(result)

result <- TASC(iris[,"Petal.Width"], method="B", tau=0.15)
print(result)
plot(result)

Binarize documentation built on May 30, 2017, 8:17 a.m.