I am using ggplot2 (respectively qplot) to generate a report with Sweave. Now I need some help with the adjustment of the size of the plot. I use the following Sweave code to include it.

\begin{figure}[htbp]
\begin{center}
<<fig=true,echo=false>>=
print(mygraph)
@
\caption{MyCaption}
\end{center}
\end{figure}

If I add a width argument (like shown below) to plot is squeezed down, but not really scaled down. 

<<fig=true,echo=false,width=3>>=

If I use ggsave() instead, I could use a scale argument and influence the size of the resulting .pdf file. Is there a way to influence the dimensions of the plot without saving it (since the .pdf is generated by Sweave anyway) ? Is there anything I need to add to my qplot code?

mygraph=qplot(date,value,data=graph1,geom="line",colour=variable,xlab="",ylab="")
+ scale_y_continuous(limits = c(-0.3,0.3))

Thx for any suggestions in advance!

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