tally: Create a tally on a biplot vector

Description

Function tally marks of a set of dots on a biplot vector. It is thought for biplot vectors representing correlations, such that their correlation scale becomes visible, without doing a full calibration with tick marks and tick mark labels.

Usage

tally(G, adj = 0, values = seq(-1, 1, by = 0.2), pch = 19, dotcolor = "black", cex = 0.5,
      color.negative = "red", color.positive = "blue")

Value

NULL

Arguments

G: Matrix with biplot coordinates of the variables
adj: A scalar adjustment for the correlations
values: The values of the correlations to be marked off by dots
pch: The character code used for marking off correlations
dotcolor: The colour of the dots that are marked off
cex: The character expansion factor for a dot.
color.negative: The colour of the segments of the negative part of the correlation scale
color.positive: The colour of the segments of the positive part of the correlation scale

Author

Jan Graffelman (jan.graffelman@upc.edu)

References

Graffelman, J. and De Leeuw, J. (2023) Improved approximation and visualization of the correlation matrix. The American Statistician pp. 1--20. tools:::Rd_expr_doi("10.1080/00031305.2023.2186952")

Examples

Run this code

data(goblets)
R <- cor(goblets)
results <- eigen(R)
V  <- results$vectors
Dl <- diag(results$values)
#
# Calculate correlation biplot coordinates
#
G  <- crossprod(t(V[,1:2]),sqrt(Dl[1:2,1:2]))
#
# Make the biplot
#
bplot(G,G,rowch=NA,colch=NA,collab=colnames(R),
      xl=c(-1.1,1.1),yl=c(-1.1,1.1))
#
# Create a correlation tally stick for variable X1
#
tally(G[1,])

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