rggplot2

Inserting a table under the legend in a ggplot2 histogram


Is there anyway to get grid.arrange() to act as split.screen ()? I would like to arrange a table to be located directly underneath the legend.

#create histogram
my_hist<-ggplot(diamonds, aes(clarity, fill=cut)) + geom_bar()

#create inset table
my_table<- tableGrob(head(diamonds)[,1:3],gpar.coretext =gpar(fontsize=8),gpar.coltext=gpar(fontsize=8), gpar.rowtext=gpar(fontsize=8))

grid.arrange(my_hist,my_table, ncol=2)

produces:

enter image description here

but I would like it look roughly like this:

enter image description here

I tried split.screen () but it doesn't seem to work with ggplot type graphics. Any suggestions? Thanks.


Solution

  • Dickoa's answer is very neat. Mine gives you more control over the elements.

    my_hist <- ggplot(diamonds, aes(clarity, fill=cut)) + geom_bar()
    
    #create inset table
    my_table <- tableGrob(head(diamonds)[,1:3], gpar.coretext = gpar(fontsize=8), gpar.coltext=gpar(fontsize=8), gpar.rowtext=gpar(fontsize=8))
    
    #Extract Legend
    g_legend <- function(a.gplot){
      tmp <- ggplot_gtable(ggplot_build(a.gplot))
      leg <- which(sapply(tmp$grobs, function(x) x$name) == "guide-box")
      legend <- tmp$grobs[[leg]]
      return(legend)}
    
    legend <- g_legend(my_hist)
    
    #Create the viewports, push them, draw and go up
    grid.newpage()
    vp1 <- viewport(width = 0.75, height = 1, x = 0.375, y = .5)
    vpleg <- viewport(width = 0.25, height = 0.5, x = 0.85, y = 0.75)
    subvp <- viewport(width = 0.3, height = 0.3, x = 0.85, y = 0.25)
    print(my_hist + opts(legend.position = "none"), vp = vp1)
    upViewport(0)
    pushViewport(vpleg)
    grid.draw(legend)
    #Make the new viewport active and draw
    upViewport(0)
    pushViewport(subvp)
    grid.draw(my_table)
    

    enter image description here