[R] plot discriminant analysis

Alejo C.S. alej.c.s at gmail.com
Wed Oct 14 14:20:07 CEST 2009

I'm confused on how is the right way to plot a discriminant analysis made by
lda function (MASS package).
(I had attached my data fro reproduction). When I plot a lda object :

X <- read.table("data", header=T)

lda_analysis <- lda(formula(X), data=X)


#the above plot is completely different to:

plot(predict(lda_analysis)$x, col=palette()[predict(lda_analysis)$class])

that should be the same graph than the first?

In the second case, I use predict function to obtain the LD1 and LD2
coordinates of lda_analysis (predict(lda_analysis)$x) and it's respective
class (predict(lda_analysis)$class), but it seems that the classes are

table(X$G3, predict(lda_analysis)$class)

        B    G   M
  B  29    0    3
  G    0  26   2
  M   4    0  46

any clues?

More information about the R-help mailing list