totvar: Total variability
In Compositional: Compositional Data Analysis
Total variability R Documentation
Total variability
Description
Total variability.
Usage
totvar(x, a = 0)
Arguments
x
A numerical matrix with the compositional data.
a
The value of the power transformation, it has to be between -1 and 1. If zero values are present it has to be greater than 0.
If \alpha=0 the centred log-ratio transformation is used.
Details
The \alpha-transformation is applied and the sum of the variances of the transformed variables is calculated.
This is the total variability. Aitchison (1986) used the centred log-ratio transformation, but we have extended it to
cover more geometries, via the \alpha-transformation.
Value
The total variability of the data in a given geometry as dictated by the value of \alpha.
Author(s)
Michail Tsagris.
R implementation and documentation: Michail Tsagris mtsagris@uoc.gr.
References
Aitchison J. (1986). The statistical analysis of compositional data. Chapman & Hall.
See Also
alfa, \ link{alfainv,} alfa.profile, alfa.tune
Examples
x <- as.matrix(iris[, 1:4])
x <- x / rowSums(x)
totvar(x)
Compositional documentation built on Oct. 9, 2024, 5:10 p.m.
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| Total variability | R Documentation |
Total variability
Description
Total variability.
Usage
totvar(x, a = 0)
Arguments
x |
A numerical matrix with the compositional data. |
a |
The value of the power transformation, it has to be between -1 and 1. If zero values are present it has to be greater than 0.
If |
Details
The \alpha-transformation is applied and the sum of the variances of the transformed variables is calculated.
This is the total variability. Aitchison (1986) used the centred log-ratio transformation, but we have extended it to
cover more geometries, via the \alpha-transformation.
Value
The total variability of the data in a given geometry as dictated by the value of \alpha.
Author(s)
Michail Tsagris.
R implementation and documentation: Michail Tsagris mtsagris@uoc.gr.
References
Aitchison J. (1986). The statistical analysis of compositional data. Chapman & Hall.
See Also
alfa, \ link{alfainv,} alfa.profile, alfa.tune
Examples
x <- as.matrix(iris[, 1:4])
x <- x / rowSums(x)
totvar(x)
R Package Documentation
Browse R Packages
We want your feedback!
Note that we can't provide technical support on individual packages. You should contact the package authors for that.
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