dt.tools {bpca} | R Documentation |
Calculates vector variable lengths, angles between vector variables and variable correlations from `data.frame' or `matrix' objects
dt.tools(x, var.position=2, var.center=TRUE, var.scale=FALSE)
x |
A data.frame or matrix object. |
var.position |
A vector of length 1 giving the position of the elements to be considered as variables on the given object. They will be represented as vectors in the graphical representation. 1 indicates rows and 2 indicates columns. |
var.center |
A logical value indicating whether the variables should be
shifted to be zero centered. Alternatively, a vector of length equal to the
number of columns of x can be supplied. The value is passed to
scale . |
var.scale |
A logical value indicating whether the variables should be
scaled to have unit variance before the analysis takes place.
Alternatively, a vector of length equal the number of columns of x can be
supplied. The value is passed to scale . |
This function computes: vector variable lengths, angles between vector
variables and variable correlations from data.frame
or
matrix
objects.
If the data are centered (var.center=TRUE), the correlations are the
same as those obtained by the cor
function.
An list with the components:
length |
A vector of the lengths. |
angle |
A matrix of the angles. |
r |
A matrix of the observed correlations. |
Jose Claudio Faria (joseclaudio.faria@gmail.com)
and
Clarice Garcia Borges Demetrio (clarice@esalq.usp.br)
Johnson, R. A. and Wichern, D. W. (1988) Applied multivariate statistical analysis. Prentice-Hall, Inc., Upper Saddle River, NJ, USA, 6 ed.
## ## Computes: vector variable lengths, angles between vector variables and ## variable correlations from dataframe or matrix objects (n x p) ## n = rows (objects) ## p = columns (variables) ## library(bpca) dt <- dt.tools(iris[-5], 2) # Exploring the object 'bp' created by the function 'var.tools' class(dt) names(dt) str(dt) dt$length dt$angle dt$r dt # Checking the determinations iris.tools <- round(dt.tools(iris[-5], var.center=TRUE)$r, 5); iris.tools iris.obsv <- round(cor(iris[-5]), 5); iris.obsv all(iris.tools == iris.obsv)