yaImpute (version 1.0-3)

yaiVarImp: Reprots or plots importance scores for method randomForest

Description

When method randomforest is used to build a yai object, the randomForest package computes variable importance scores. This function computes a composite of the scores and scales them. By default the scores are plotted and scores themselves are invisibly returned.

Usage

yaiVarImp(object, nTop=20, plot=TRUE, ...)

Arguments

object

an object of class yai

nTop

the nTop most important variables are plotted (returned); if NA or zero, all are returned

plot

if FALSE, no plotting is done, but the scores are returned.

...

passed to boxplot function.

Value

• A data frame with the rows corresponding to the randomForest built for each Y-variable and the columns corresponding to the nTop most important Y-variables in sorted order.

See Also

yai, yaiRFsummary, compare.yai

Examples

data(MoscowMtStJoe)

# get the basal area by species columns
yba  <- MoscowMtStJoe[,1:17]
ybaB <- whatsMax(yba,nbig=7)  # see help on whatsMax

ba <- cbind(ybaB,TotalBA=MoscowMtStJoe[,18])
x <- MoscowMtStJoe[,37:64]
x <- x[,-(4:5)]
rf <- yai(x=x,y=ba,method="randomForest")

yaiVarImp(rf)

keep=colnames(yaiVarImp(rf,plot=FALSE,nTop=9))

newx <- x[,keep]
rf2 <- yai(x=newx,y=ba,method="randomForest")

yaiVarImp(rf2,col="gray")

compare.yai(rf,rf2)