sym_cuni_cn {noisemodel}

Symmetric completely-uniform combined noise

Description

Introduction of Symmetric completely-uniform combined noise into a classification dataset.

Usage

## Default S3 method:
sym_cuni_cn(x, y, level, sortid = TRUE, ...)

## S3 method for class 'formula'
sym_cuni_cn(formula, data, ...)

Arguments

x

a data frame of input attributes.

y

a factor vector with the output class of each sample.

level

a double in [0,1] with the noise level to be introduced.

sortid

a logical indicating if the indices must be sorted at the output (default: TRUE).

...

other options to pass to the function.

formula

a formula with the output class and, at least, one input attribute.

data

a data frame in which to interpret the variables in the formula.

Details

Symmetric completely-uniform combined noise corrupts (level·100)% of the values of each attribute in the dataset. In order to corrupt an attribute A, (level·100)% of the samples in the dataset are randomly chosen. Then, their values for A are replaced by random ones from the domain of the attribute.

Additionally, this noise model also selects (level·100)% of the samples in the dataset with independence of their class. The labels of these samples are randomly replaced by other ones within the set of class labels.

Note that, for both attributes and class labels, the original value of a sample can be chosen as noisy and the actual percentage of noise in the dataset can be lower than the theoretical noise level.

Value

An object of class ndmodel with elements:

xnoise

a data frame with the noisy input attributes.

ynoise

a factor vector with the noisy output class.

numnoise

an integer vector with the amount of noisy samples per variable.

idnoise

an integer vector list with the indices of noisy samples per variable.

numclean

an integer vector with the amount of clean samples per variable.

idclean

an integer vector list with the indices of clean samples per variable.

distr

an integer vector with the samples per class in the original data.

model

the full name of the noise introduction model used.

param

a list of the argument values.

call

the function call.

Note

Noise model adapted from the papers in References.

References

C. Teng. Polishing blemishes: Issues in data correction. IEEE Intelligent Systems, 19(2):34-39, 2004. doi:10.1109/MIS.2004.1274909.

See Also

uncs_guni_cn, sym_cuni_an, print.ndmodel, summary.ndmodel, plot.ndmodel

Examples

# load the dataset
data(iris2D)

# usage of the default method
set.seed(9)
outdef <- sym_cuni_cn(x = iris2D[,-ncol(iris2D)], y = iris2D[,ncol(iris2D)], level = 0.1)

# show results
summary(outdef, showid = TRUE)
plot(outdef)

# usage of the method for class formula
set.seed(9)
outfrm <- sym_cuni_cn(formula = Species ~ ., data = iris2D, level = 0.1)

# check the match of noisy indices
identical(outdef$idnoise, outfrm$idnoise)