\section{Launch my first FA$\mu$ST operator}\label{sec:firstUse}
\section{QuickStart}\label{sec:firstUse}
A matlab wrapper is used to launch the FAUST C++ library.
A matlab wrapper is delivered with the FAUST C++ library.
It provides a user friendly new class of matrix \textbf{matlab{\_}faust} efficient for the multiplication with matlab built-in dense matrix class.\newline
\newline
As much as possible, a \textbf{matlab{\_}faust} object is handled as a normal matlab matrix, here is listing of matlab builtin function that can be applied to a faust A :
\begin{lstlisting}
>> % considering A is a Faust of size 10x3
>>
>> % get the size of the faust
>> [dim1,dim2] = size(A);
>>
>> % transpose a faust
>> A_trans = A';
>>
>> % multiplication by A
>> x1 = rand(3,3);
>> y1 = A*x1;
>>
>> % multiplication by A'
>> x2 = rand(10,5);
>> y2 = A'*x2;
\end{lstlisting}
\subsection{construct a faust}\label{sec:firstUseBuild}
A \textbf{matlab{\_}faust} object can be constructed from several ways.
\subsubsection{construct a faust from a cell-array}\label{sec:firstUseBuildFromCellArray}
First, you can build a faust from a cell-array of matlab matrix (sparse or dense) representing its factors.
\newline
\newline
The following example shows how to build a random faust of size 5x3 with 3 factors :
\begin{lstlisting}
>> nb_factor = 3;
>> dim1 = 5;
>> dim2 = 3;
>>
>> % list of factors
>> factors = cell(nb_factor);
>>
>> factors{1}=rand(dim1,dim2); % first factor is rectangular
>> for i=2:nb_factor
>> factors{i}=rand(dim2,dim2);
>> end
>>
>> % build the faust
>> A=matlab_faust(factors);
\end{lstlisting}
\newpage
An optional multiplying scalar argument can be taken into account :
\begin{lstlisting}
>> % multiplicative scalar
>> lambda = 3.5
>> % build the faust
>> A=matlab_faust(factors,lambda);
\end{lstlisting}
This functionality allows you to build a faust from the factorization algorithm :
\textbf{mexHierarchical{\_}fact} or \textbf{mexPalm4MSA} :
\begin{lstlisting}
>> % factorization step
>> [lambda,factors]=mexHierarchical_fact(params);
>> % build the faust corresponding to the factorization
>> A=matlab_faust(factors,lambda);
\end{lstlisting}
\subsubsection{construct a faust from a saved one}\label{sec:firstUseBuildFromSave}
You can also build a faust from a previously one which is saved into a mat file :
