Hi, I use the lda function from the MASS package to classify some
samples according to some chemical properties. If I run lda without
cross validation all is ok but, if I run lda with cross validation,
the R consol say:
resLDA <- ldaRedOx <- lda(Activity ~ TRedOx[,1:6], CV=TRUE,
data=dfDataRedOx, subset=train)
predLDA <- predict(resLDA, newdata=dfDataRedOx[-train,])$class
> predLDA <- predict(resLDA, newdata=dfDataRedOx[-train,])$class
Error in UseMethod("predict") :
no applicable method for 'predict' applied to an object of class
"list"
>
How should I use predict function with lda with the cross validation?
Best
Riccardo
Error predict with lda and cross validation
2 messages · Riccardo Romoli, Uwe Ligges
On 17.01.2012 14:54, Riccardo Romoli wrote:
Hi, I use the lda function from the MASS package to classify some samples according to some chemical properties. If I run lda without cross validation all is ok but, if I run lda with cross validation, the R consol say: resLDA <- ldaRedOx <- lda(Activity ~ TRedOx[,1:6], CV=TRUE, data=dfDataRedOx, subset=train) predLDA <- predict(resLDA, newdata=dfDataRedOx[-train,])$class
> predLDA <- predict(resLDA, newdata=dfDataRedOx[-train,])$class
Error in UseMethod("predict") :
no applicable method for 'predict' applied to an object of class "list"
>
How should I use predict function with lda with the cross validation?
See ?lda : it has a very different output if CV=TRUE is used. Hence you have to prepare it with CV=FALSE in order to make predictions again. It does not make sense to ask LDA for a cross validation an run another test later on, does it? Uwe Ligges
Best Riccardo
______________________________________________ R-help at r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.