rppa.selectFactors <- function(spots, factor="SampleName")

{

require(tcltk)

tt<-tktoplevel()

tl<-tklistbox(tt,height=10,selectmode="multiple",background="white")

tkgrid(tklabel(tt,text="Please select factors to include."))

tkgrid(tl)

spotNames <- levels(spots[[factor]])

for (i in (1:length(spotNames)))

{

tkinsert(tl,"end",spotNames[i])

}

tkselection.set(tl,0) rm

OKSelection <- function()

{

spotNames <<- as.integer(tkcurselection(tl))

tkdestroy(tt)

}

OK.but <-tkbutton(tt,text=" OK ",command=OKSelection)

tkgrid(tklabel(tt,text=" "))

tkgrid(OK.but)

tkfocus(tt)

tkwait.window(tt)

spotNames <- spotNames + 1

return(spots[spots$SampleName %in% levels(spots$SampleName)[spotNames],])

}