\section{WHILE While Loop}

\subsection{Usage}

The \verb|while| loop executes a set of statements as long as
a the test condition remains \verb|true|.  The syntax of a 
\verb|while| loop is
\begin{verbatim}
  while test_expression
     statements
  end
\end{verbatim}
Note that a conditional expression is considered true if 
the real part of the result of the expression contains
any non-zero elements (this strange convention is adopted
for compatibility with MATLAB).
\subsection{Examples}

Here is a \verb|while| loop that adds the integers from \verb|1|
to \verb|100|:
\begin{verbatim}
--> accum = 0;
--> k=1;
--> while (k<100), accum = accum + k; k = k + 1; end
--> accum

ans = 

 4950 


\end{verbatim}
\begin{verbatim}
    testeq.m
function x = testeq(a,b)
  if (size(a,1) ~= size(b,1) || size(a,2) ~= size(b,2))
    x = 0;
    return;
  end
  d = full(a)-full(b);
  if (strcmp(typeof(d),'double') | strcmp(typeof(d),'dcomplex'))
    x = isempty(find(abs(d)>10*eps));
  else
    x = isempty(find(abs(d)>10*feps));
  end
\end{verbatim}
