\section{Virtual\_input: Starting the second part of a split simulation}
\label{s:virtual-input}
\index{Sources!Virtual source from stored neutron events}
\mcdoccomp{misc/Virtual_input.parms}

The component \textbf{Virtual\_input} resumes a split simulation where the
first part has been performed by another instrument and the photon ray
parameters have been stored by the component \textbf{Virtual\_output}.

All photon ray parameters are read from the input file, which is by default
of ``text'' \textit{type}, but can also assume the binary formats
``float'' and ``double''. Reading of photon rays continues until the
specified number of rays have been simulated or
the file has been exhausted. If desirable, the input file
can be reused a number of times, determined by the optional parameter
\textit{repeat-count}. This is only useful if the present simulation makes use of
MC choices, otherwise the same outcome will result for each repetition of the
simulation (see \cref{c:MCtechniques}).

Care should be taken when dealing with
absolute intensities, which will be correct only
when the input file has been exhausted at least once.

The simulation ends with either the end of the repeated file counts,
or with the normal end with $ncount$ \MCX\ simulation events. We recommend
controlling the simulation on \textit{repeat-count} by using
a larger ncount value.
