Hello, I used the lda function from the MASS (VR) package and the rda function from the klaR package. I wanted to compare the result of this two functions by using the same training set. Thus, I used the rda function with lambda=1 an gamma=0, I should emulate the lda function and I should obtain the same result. But this it not the case, the two result are very different. My training set is 70 observations * 10 variables long, and I performed a leave one out for each observations. Do somebody have an idea for the cause(s) of this? Thanks Trolet Julien
Lda versus Rda
2 messages · Julien Trolet, Uwe Ligges
Julien Trolet wrote:
Hello, I used the lda function from the MASS (VR) package and the rda function from the klaR package. I wanted to compare the result of this two functions by using the same training set. Thus, I used the rda function with lambda=1 an gamma=0, I should emulate the lda function and I should obtain the same result. But this it not the case, the two result are very different. My training set is 70 observations * 10 variables long, and I performed a leave one out for each observations. Do somebody have an idea for the cause(s) of this?
With the iris data, the following works for me: x1 <- predict(lda(Species~., data=iris)) x2 <- predict(rda(Species~., data=iris, lambda=1, gamma=0)) all(x1$class == x2$class) all.equal(x1$posterior, x2$posterior) So, can you specify an example (including data + code, in a private message) please? If your analysis for your data is correct, the error is probably in rda(). I won't have time to look at it before monday (and the author of the rda() code is in Auckland these days). It's always a good idea to ask the package maintainer first, BTW. Uwe Ligges
Thanks Trolet Julien