# Linear Discriminant Analysis with unequal sample sizes

I am performing an LDA with very unequal sample size (ratio 1:10) among 3 groups. The results surprise me, as I was expected from a series of boxplot that some variables that explain much of the between group variance to show up on at least one of the first two axes but they don't. This yield me to the question:

Should unequal sample size be taken into account when performing Linear Discrimant Analysis?

If it matters, I am using the lda function from the MASSpackage in R with all the default parameters.

• some variables that explain much of the between group variance to show up on at least one of the first two axes What do you mean? unwrap please. Are "axes" the discriminants? If yes why "at least first two"? (you have only two with 3 groups) Is "show up" discriminant weights or what? How you estimate how "much a variable explain of the b/w group variance? Etc. I think you ought also to show and even to give your data. – ttnphns Jan 25 '17 at 23:40

lda  <- lda(class ~ v1 + v2, data = data)