The document that follows has been generated from original Sweave
(\textbf{.Rnw}) files. Details are in the document
\textbf{Sweave-info.pdf}.
\section{Command Line Calculations}
[In the book, calculations are mostly performed by typing commands on
the command line.] Practice in the evaluation of arithmetic
expressions will help develop the needed conceptual and keyboard
skills. Here are simple examples:
<>=
2*3*4*5 # * denotes 'multiply'
sqrt(10) # the square root of 10
pi # R knows about pi
2*pi*6378 # Circumference of earth at equator (km)
# (radius at equator is 6378 km)
@%
{\small \noindent
\textbf{Note:} Unfortunately, \texttt{Sweave()} strips any comments
from the code. The code that was input to Sweave was:
\begin{verbatim}
2*3*4*5 # * denotes 'multiply'
sqrt(10) # the square root of 10
pi # R knows about pi
2*pi*6378 # Circumference of earth at equator (km)
# (radius at equator is 6378 km)
\end{verbatim}
}
\section{Plotting a Graph}
Type in data and draw Figure 1:
\begin{figure}[H]
\begin{center}
<>=
Year <- c(1800, 1850, 1900, 1950, 2000)
Carbon <- c(8, 54, 534, 1630, 6611)
## Now plot Carbon as a function of Year
plot(Carbon ~ Year, pch=16)
@
\caption{Plot of annual totals of carbon emissions (millions of tonnes),
against year}
\end{center}
\end{figure}