unc_vgau_an {noisemodel}

Unconditional vp-Gaussian attribute noise

Description

Introduction of Unconditional vp-Gaussian attribute noise into a classification dataset.

Usage

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

## S3 method for class 'formula'
unc_vgau_an(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

In Unconditional vp-Gaussian attribute noise, the noise level for numeric attributes indicates the magnitude of the errors introduced. For each attribute A, all the original values are corrupted by adding a random number that follows a Gaussian distribution with mean = 0 and variance = level% of the variance of A. For nominal attributes, (level·100)% of the samples in the dataset are chosen and a random value is selected as noisy.

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 attribute.

idnoise

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

numclean

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

idclean

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

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, corrupting all samples and allowing nominal attributes.

References

X. Huang, L. Shi, and J. A. K. Suykens. Support vector machine classifier with pinball loss. IEEE Transactions on Pattern Analysis and Machine Intelligence, 36(5):984-997, 2014. doi:10.1109/TPAMI.2013.178.

See Also

symd_rpix_an, unc_fixw_an, print.ndmodel, summary.ndmodel, plot.ndmodel

Examples

# load the dataset
data(iris2D)

# usage of the default method
set.seed(9)
outdef <- unc_vgau_an(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 <- unc_vgau_an(formula = Species ~ ., data = iris2D, level = 0.1)

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