dt.tools {bpca} R Documentation

## Data Tools for Multivariate

### Description

Calculates vector variable lengths, angles between vector variables and variable correlations from ‘data.frame’ or ‘matrix’ objects

### Usage

dt.tools(x,
center=2,
scale=TRUE)

### Arguments

 x A data.frame or matrix object. center Numeric. The type of centering to be performed: ‘⁠0⁠’ - no centering; ‘⁠1⁠’ - global-centered = sweep(x, 1, mean(x)); ‘⁠2⁠’ - column-centered = sweep(x, 2, apply(x, 2, mean)); ‘⁠3⁠’ - double-centered = sweep(sweep(x, 1, apply(x, 1, mean)), 2, apply(x, 2, mean)) + mean(x). The default is 2. scale Logical. A value indicating whether the variables should be scaled to have unit variance before the analysis takes place: FALSE - no scale; TRUE - scale.

### Details

This function computes: vector variable lengths, angles between vector variables and variable correlations from data.frame or matrix objects.

If the data are centered (center=2), the correlations are the same as those obtained by the cor function.

### Value

An list with the components:

 length A vector of the lengths. angle A matrix of the angles. r A matrix of the observed correlations.

### Author(s)

Faria, J. C.
Allaman, I. B.
Demétrio C. G. B.

### References

Johnson, R. A. and Wichern, D. W. (1988) Applied multivariate statistical analysis. Prentice-Hall, Inc., Upper Saddle River, NJ, USA, 6 ed.

bpca

### Examples

##
## Computes: vector variable lengths, angles between vector variables and
## variable correlations from data.frame or matrix objects (n x p)
## n = rows (objects)
## p = columns (variables)
##

dt <- dt.tools(iris,
2)  # No numeric columns are removed in dt.tools

# Exploring the object 'bp' created by the function 'var.tools'
class(dt)
names(dt)
str(dt)

dt$length dt$angle
dt$r dt # Checking the determinations (iris.tools <- round(dt.tools(iris, center=2)$r,
5))

(iris.obsv  <- round(cor(iris[-5]),
5))

all(iris.tools == iris.obsv)

[Package bpca version 1.3-6 Index]