prevent print() from outputting list indices in R

Question

I have a list containing 6 plots, made like this:

voi=c('inadist','smldist','lardist')
plist<-llply(voi, function(v,df,s) {
            list(   assign(paste(v,'.violin'), bwplot(groupname~df[,which(colnames(df)==v)]|fCycle*fPhase, data=df, groups=groupname, col=rainbow(1), box.ratio=3,
                                    main=paste('Distribution of ', v, ' by Treatment and Cycle'),sub=s, xlab=v, panel=panel.violin)),
                    assign(paste(v,'.hexbin'),hexbinplot(df[,which(colnames(df)==v)]~starttime|groupname, data=df,
                                xlab='Time(s)',main= paste('Distribution of ',v,' by Treatment'),sub=s,ylab=v,
                                aspect=0.5, colramp=redgrad.pal, layout=c(2,4)))

            )
        },data,meta$exp_name)

If I print the list, print(plist), the plots are output to the graphical device, then the indices are output to the console resulting in this:

[[1]]
[[1]][[1]]

[[1]][[2]]


[[2]]
[[2]][[1]]

[[2]][[2]]


[[3]]
[[3]][[1]]

[[3]][[2]]

Because I am coding a webapp, I need to control console output quite strictly. So far the only way I can output the plots without outputting the indices is like this:

for(p in plist) for(i in p) print(i)

Is there a more efficient way of getting what I need?

Answer 1

You can cheat with capture.output:

dummy <- capture.output(print(plist))

or without creating a new variable

invisible(capture.output(print(plist)))

---

By the way, reproducible example look like this:

require(lattice)
plist <- list(
    list(bwplot(rnorm(10)),bwplot(rnorm(10))),
    list(bwplot(rnorm(10)),bwplot(rnorm(10))),
    list(bwplot(rnorm(10)),bwplot(rnorm(10)))
)

Answer 2

Another hack :

library(plyr)
library(lattice)

plist <- list(
    bwplot(voice.part ~ height, data=singer, xlab="Height (inches)"),
    dotplot(variety ~ yield | year * site, data=barley)
)

x <- lapply(plist,print)
rm(x)