unable to run knitr to produce a pdf output file

问题

I have sweave file like this:

test.rnw

\documentclass[letter,10pt]{article}

\usepackage{amsmath}
\usepackage{amscd}

\usepackage{ifthen}
\usepackage[utf8]{inputenc}
\usepackage{hyperref}
\usepackage[top=1.0in, bottom=1.0in, left=0.75in, right=0.75in]{geometry}


\begin{document}
\title{Top areas of focus for \\ This is a test}
\author{ test }
\maketitle
\pagebreak
\tableofcontents
\pagebreak

\section{Introduction}
this is a test document

\end{document}

I am trying to manually run knitr agaist it and produce a pdf file like this:

 knit2pdf("test.rnw", "test.pdf", compiler="texi2pdf")

I am getting an error:

running command '"G:\latex\latex\miktex\bin\x64\texi2dvi.exe" --quiet --pdf "test.pdf"  -I "G:/R/R-2.15.2/share/texmf/tex/latex" -I "G:/R/R-2.15.2/share/texmf/bibtex/bst"' had status 1 

I am very new to knitr, can anybody tell me what I am doing wrong? Basically I would like to combile an .rnw file and output it to a pdf file.

来源：https://stackoverflow.com/questions/14508429/unable-to-run-knitr-to-produce-a-pdf-output-file