| deleteNearZeroCoefficientOfVariation {Coxmos} | R Documentation |
deleteNearZeroCoefficientOfVariation
Description
Filters out variables from a dataset that exhibit a coefficient of variation below a specified threshold, ensuring the retention of variables with meaningful variability.
Usage
deleteNearZeroCoefficientOfVariation(X, LIMIT = 0.1)
Arguments
X |
Numeric matrix or data.frame. Explanatory variables. Qualitative variables must be transform into binary variables. |
LIMIT |
Numeric. Cutoff for minimum variation. If coefficient is lesser than the limit, the variables are removed because not vary enough (default: 0.1). |
Details
The deleteNearZeroCoefficientOfVariation function is a pivotal tool in data preprocessing,
especially when dealing with high-dimensional datasets. The coefficient of variation (CoV) is a
normalized measure of data dispersion, calculated as the ratio of the standard deviation to the mean.
In many scientific investigations, variables with a low CoV might be considered as offering
limited discriminative information, potentially leading to noise in subsequent statistical analyses.
By setting a threshold through the LIMIT parameter, this function provides a systematic approach
to identify and exclude variables that do not meet the desired variability criteria. The underlying
rationale is that variables with a CoV below the set threshold might not contribute significantly
to the variability of the dataset and could be redundant or even detrimental for certain analyses.
The function returns a modified dataset, a list of deleted variables, and the computed coefficients
of variation for each variable. This comprehensive output ensures that researchers are well-informed
about the preprocessing steps and can make subsequent analytical decisions with confidence.
Value
Return a list of two objects:
X: The new data.frame X filtered.
variablesDeleted: The variables that have been removed by the filter.
coeff_variation: The coefficient variables per each variable tested.
Author(s)
Pedro Salguero Garcia. Maintainer: pedsalga@upv.edu.es
Examples
data("X_proteomic")
X <- X_proteomic
filter <- deleteNearZeroCoefficientOfVariation(X, LIMIT = 0.1)