\section{Progress\_bar: Dynamic information output}
\label{s:progress-bar}
\index{Optics!Progress bar}
\mcdoccomp{misc/Progress_bar.parms}

The component \textbf{Progress\_bar} is a special version of an Arm and has no effect on the x-ray.
Only one instance of progress bar is allowed - usually it is the very first component of a beamline simulation.

If \textit{percent}$>0$ (default is $10\%$) the porgress bar prints an update when approximately \textit{percent \% } of the total number of rays
have been simulated. If \textit{minutes}$>0$ (overrides \textit{percen}) this update happens approx. every \textit{minutes} min.
If \textit{flag\_save}$\ne 0$, the update process also includes saving the status of all monitors to disk. This is useful if something is likely to interrupt the progress of long simulations ot avoid loss of data.
\textit{profile} may be set to save the simulation profile to a filename other than the name of the instrument (the default).
