

\subsection{\bf Monte Carlo Approach}
\subsection{\bf to Discrete Integrals}

\begin{slide}
\begin{itemize}
\item (iv) Discrete Integrals

\item One can apply Monte Carlo methods to sums as well as
continuous integrals.  For example, suppose we have to calculate
$$
\int dx_a\, dx_b\, dx_c\, \ldots \sum^2_{l=1} f_l\,\left(x_a, x_b,
x_c \ldots\right)
$$
\item Then generate using normal Monte Carlo approach with random
numbers to generate $x_a$, $x_b$, $x_c$.

\item Now, generate another random number $r$ with $0\le r\le 1$
uniformly and then code
\begin{eqnarray*}
\mbox{if}\ \ ( r < 0.5 )\ l & = & 1 \\
\mbox{else}\ \ l & = & 2 \\
\end{eqnarray*}
\item and obvious modifications for other discrete summations.
\end{itemize}
\end{slide}

