TASC {BiTrinA} R Documentation

## Trinarization Across Multiple Scales

### Description

Trinarizes real-valued data using the multiscale TASC method.

### Usage

```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

```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)
```

[Package BiTrinA version 1.3 Index]