Momocs (version 1.1.6)

scree: Methods for PCA eigen values

Description

A set of functions around PCA/LDA eigen/trace. scree calculates their proportion and cumulated proportion; scree_min returns the minimal number of axis to use to retain a given proportion; scree_plot displays a screeplot.

Usage

scree(x, nax)
# S3 method for PCA
scree(x, nax = 1:10)
# S3 method for LDA
scree(x, nax = 1:10)
scree_min(x, prop = 0.99)
scree_plot(x, nax = 1:10)

Arguments

x

a PCA object

nax

numeric range of axis to consider

prop

numeric how many axis are enough this proportion of variance, if too high then number of axis is returned.

Value

scree returns a data.frame, scree_min a numeric, scree_plot a ggplot.

Examples

data(bot)
# On PCA
bp <- PCA(efourier(bot))
scree(bp)
scree_min(bp, 0.99)
scree_min(bp, 1)

scree_plot(bp)
scree_plot(bp, 1:5)

# on LDA, it uses svd
data(olea)
bl <- LDA(PCA(opoly(olea)), "var")
scree(bl)