当我在这个knitr文档的输出上运行LaTeX时，LaTeX会崩溃，因为LaTeX特殊字符没有被正确转义。有什么提示如何解决这个问题？
\documentclass{beamer}
\begin{document}
\begin{frame}{Unescaped dollar signs and tildes}
In this example, neither the tilde nor the dollar sign
will appear in the pdf document, and the dollar sign
will cause a \LaTeX error.
<<xtable, results="asis">>=
n <- 100
x <- rnorm(n)
y <- 2*x + rnorm(n)
out <- lm(y ~ x)
library(xtable)
xtable(summary(out)$coef, digits=c(0, 2, 2, 1, 2))
@
\end{frame}
\end{document}