Using ggvis in Rnw with knitr

I wonder if I can use ggvis in .Rnw with knitr. I tried the following code in RStudio Version 0.98.1091. But it is not working.

\documentclass{book}
\usepackage[T1]{fontenc}
\usepackage{float}
\usepackage{booktabs}
\usepackage{dcolumn}
\usepackage{geometry}
\geometry{verbose,tmargin=2cm,bmargin=2cm,lmargin=2cm,rmargin=2cm}

\begin{document}
\chapter{Test}
\begin{figure}[H]
<< label = Plot1, fig.lp = "Plot1", fig.cap = "Test Plot" >>=
library(ggvis)
p <- mtcars %>% ggvis(x = ~wt, y = ~mpg) %>% layer_points()
print(p)     # Commenting this line will compile the document
@
\end{figure}
\end{document}

It throws the following error:

LaTeX errors:
! Missing $ inserted.
<inserted text> 
                $
l.70 \end{kframe}<!--html_
                          preserve--><div id="plot_id298740869-container" cl...
! Please use \mathaccent for accents in math mode.

Any help will be highly appreciated. Thanks

Edited

Commenting the line print(p) will compile the document without any error.

Would be sufficient if there is a command like ggsave() to save the ggvis plots.

Yes.

The export_png function can create a PNG image from a ggvis object.

It uses the node javascript interpreter, and node needs the vega package installed.

At the linux command line, I can do this with:

sudo npm -g install vega

to install the vega package globally using the node package manager. I don't know how you do this on a Windows or Mac box.

Once that's done, you can:

\documentclass{book}
\usepackage[T1]{fontenc}
\usepackage{float}
\usepackage{booktabs}
\usepackage{dcolumn}
\usepackage{geometry}
\geometry{verbose,tmargin=2cm,bmargin=2cm,lmargin=2cm,rmargin=2cm}

\begin{document}
\chapter{Test}
\begin{figure}[H]
<< label = Plot1, fig.lp = "Plot1", fig.cap = "Test Plot" >>=
library(ggvis)
p <- mtcars %>% ggvis(x = ~wt, y = ~mpg) %>% layer_points()
export_png(p,"Plot1.png")    
@
\includegraphics[width=0.8\textwidth]{Plot1.png}
\end{figure}
\end{document}

do: knit2pdf("gg.Rnw")

and get:

Note you'll have to add captions and labels manually. Perhaps Yihui can be persuaded to integrate this better into knitr, or there may be a way using some of the knitr hooks. Anyway, concept proved...