Type 'mcgui' at prompt (mcgui.pl on Windows).
Select the Neutron site menu, and the Brookhaven/H8 instrument as a test.
Click on the Edit button of the McGUI interface (right side). An editor with highlight syntaxing appears, showing the instrument description [h8_test.instr]. It enables to insert components easily from the Component Library.
Select on the Help menu of the McGUI interface (right side).
A browser shows components and instruments available, as well as links to the Manuals and the Data Base.
Click on the Run button of the McGUI interface (right side). The current instrument is compiled and finally the Run Dialog appears. From there you may request single simulations, scan of parameters (series of simulations), optimization of instrument parameters and geometry view of the instrument. Multi-processing is also available.
In the example, we have requested a scan of the Lambda parameter of [h8_test.instr]
Each simulation result can be view either as an overview of all instrument monitors, or looking at each monitor data.
Data files are usually saved as text, using the original McStas format, or Matlab, Scilab, IDL, XML, HTML/VRML, Octave, ...
Click on the Plot button of the McGUI interface. When simulating a scan of a parameter, the simulation produces the integral value of monitors as a function of the scan parameters.
In the Run Dialog, you may choose the '3D Trace' execution mode. A view of the instrument is then produced. Neutron trajectories can be followed. Rather use a limited number of neutrons.
The VRML view is specially nice to walk around.