Why does 2nd ggplot not appear using knitr and grid?

Question

I am trying to create a document using knitr that includes ggplot2 plots modified using grid.

In the example below, there

Answer 1

adding code from comments

I added a grid.newpage() before the second plot to allow both to render. Also had to tweak the margins to get the annotations to show.

Sp your code is

\documentclass{article}

\begin{document}

<< fig.cap = c('color', 'clarity')>>=
library(ggplot2)
library(grid)

# Create plot with color

p = ggplot(diamonds,aes(cut,fill = color)) + geom_bar(position = 'fill') + annotate('text', label = as.character(table(diamonds$cut)), x = 1:5, y = Inf, vjust = -1) + 
theme(plot.margin=unit( c(2,1,1,1), "lines") ) ### added

gt = ggplot_gtable(ggplot_build(p))
gt$layout$clip[gt$layout$name == 'panel'] = 'off'
grid.draw(gt)

# Create plot with clarity

q = ggplot(diamonds,aes(cut,fill = clarity)) + geom_bar(position = 'fill') + annotate('text', label = as.character(table(diamonds$cut)), x = 1:5, y = Inf, vjust = -1) + 
theme(plot.margin=unit( c(2,1,1,1), "lines") ) ### added

gs = ggplot_gtable(ggplot_build(q))
gs$layout$clip[gs$layout$name == 'panel'] = 'off'
grid.newpage() ## This is the extra line
grid.draw(gs)
@

\end{document}