I want to be able to print out non-predetermined list of plots in knitr. I *am* able to do that, but there are a few wrinkles left to iron out. Namely:

1) How do you suppress the list indices (like [[2]]) on each page that precede each plot? Using echo=FALSE doesn't do anything. 

2) Is it possible to set the size for *each plot* as they are rendered? I've tried setting a size variable outside of the chunk, but that only lets me use one value and not a different value per plot. 

I'm asking this as one question because they seem to speak to the same lesson, i.e., producing a list of plots. 

Some sample code:

```
\documentclass{article}
\usepackage[margin=.5in, landscape]{geometry}
\begin{document}

<<diamond_plots, echo = FALSE, results = 'hide'>>==
library(ggplot2)

diamond_plot = function(data, cut_type){
  ggplot(data, aes(color, fill=cut)) + 
    geom_bar() +
    ggtitle(paste("Cut:", cut_type, sep = ""))
}

cuts = unique(diamonds$cut)
plots = list()
for(i in 1:length(cuts)){
    data = subset(diamonds, cut == cuts[i])
    plots[[i]] = diamond_plot(data, cuts[i])
}
height = 3
@

<<print_plots, results='asis', echo=FALSE,  fig.width=10, fig.height=height>>=
plots
@
\end{document}

```

The PDF of the plots looks like this:

[![enter image description here](https://i.stack.imgur.com/rhams.png)](https://i.stack.imgur.com/rhams.png)