R code and Sweave output - EDIT

Question

UPDATED Question 1 In the lattest update of KnitR the output is clean as what I expected. Maybe an update was made.

The new output :

Before update

I'm trying to get a particular output with Sweave and R code. For now I have this code :

\documentclass[11pt,french]{report}
  \usepackage{babel} %%french
  \usepackage{amsmath,amsfonts,amssymb} %%maths
  \usepackage[utf8]{inputenc}   % LaTeX
  \usepackage[T1]{fontenc}      % LaTeX
  \usepackage[dvipsnames,table,xcdraw]{xcolor}
  %% Background code chunk
  \usepackage{listings}
  \usepackage{color}

  \definecolor{codegreen}{rgb}{0,0.6,0}
  \definecolor{codegray}{rgb}{0.5,0.5,0.5}
  \definecolor{codepurple}{rgb}{0.58,0,0.82}
  \definecolor{backcolour}{rgb}{0.95,0.95,0.92}
 %% background code chunk listing
  \lstset{
    language=R}
\lstdefinestyle{mystyle}{
    backgroundcolor=\color{backcolour},   
    commentstyle=\color{codegreen},
    keywordstyle=\color{magenta},
    numberstyle=\tiny\color{codegray},
    stringstyle=\color{codepurple},
    basicstyle=\footnotesize,
    breakatwhitespace=false,         
    breaklines=true,                 
    captionpos=b,                    
    keepspaces=true,                 
    numbers=left,                    
    numbersep=5pt,                  
    showspaces=false,                
    showstringspaces=false,
    showtabs=false,                  
    tabsize=2
}

\lstset{style=mystyle}

witch is coming from this site.

The R code I'm trying to implement is :

%% script R
\begin{lstlisting}[linerange=\\begin\{Sinput\}-\\end\{Sinput\},includerangemarker=false, caption = Code source en R pour l'exemple]
<<eval =FALSE>>=
# dataset
x <- c(2,3,6,9,12); y <- c(2,5,3,6,5)

# Estimations des parametres
reg <- lm(y ~ x)

# Resume de l'estimation
summary(reg)

# Valeurs de Yt
fitted(reg)

# Residus 
residuals(reg)
@
\end{lstlisting}

The output :

My questions :

1- How can I get a better output for the ~ symbol ?

2- Is there a way to eval the code without getting and output like this ?

Answer 1

The solution for question 2.

<<eval = TRUE, echo=FALSE, fig=TRUE, height=4,width=4.5>>=
[...] precedent code
@

The solution is just to add echo=false and eval=false for preventing the \begin{Schunk} and other Tex command.