dist.quant {ade4}R Documentation

Computation of Distance Matrices on Quantitative Variables

Description

computes on quantitative variables, some distance matrices as canonical, Joreskog and Mahalanobis.

Usage

dist.quant(df, method = NULL, diag = FALSE, upper = FALSE, 
    tol = 1e-07)

Arguments

df a data frame containing only quantitative variables
method an integer between 1 and 3. If NULL the choice is made with a console message. See details
diag a logical value indicating whether the diagonal of the distance matrix should be printed by ‘print.dist’
upper a logical value indicating whether the upper triangle of the distance matrix should be printed by ‘print.dist’
tol used in case 3 of method as a tolerance threshold for null eigenvalues

Details

All the distances are of type d = ||x-y||_A = sqrt((x-y)^t A (x-y))

1 = Canonical
A = Identity
2 = Joreskog
A = 1 / diag(cov)
3 = Mahalanobis
A = inv(cov)

Value

an object of class dist

Author(s)

Daniel Chessel
St├ęphane Dray dray@biomserv.univ-lyon1.fr

Examples

data(ecomor)
par(mfrow = c(2,2))
scatter(dudi.pco(dist.quant(ecomor$morpho,3), scan = FALSE))
scatter(dudi.pco(dist.quant(ecomor$morpho,2), scan = FALSE))
scatter(dudi.pco(dist(scalewt(ecomor$morpho)), scan = FALSE))
scatter(dudi.pco(dist.quant(ecomor$morpho,1), scan = FALSE))
par(mfrow = c(1,1))

Worked out examples


> library(ade4)
> ### Name: dist.quant
> ### Title: Computation of Distance Matrices on Quantitative Variables
> ### Aliases: dist.quant
> ### Keywords: array multivariate
> 
> ### ** Examples
> 
> data(ecomor)
> par(mfrow = c(2,2))
> scatter(dudi.pco(dist.quant(ecomor$morpho,3), scan = FALSE))
> scatter(dudi.pco(dist.quant(ecomor$morpho,2), scan = FALSE))
> scatter(dudi.pco(dist(scalewt(ecomor$morpho)), scan = FALSE))
> scatter(dudi.pco(dist.quant(ecomor$morpho,1), scan = FALSE))
> par(mfrow = c(1,1))
> 
> 
> 

[Package ade4 Index]