GYOTOY(1)							   User Manuals 							 GYOTOY(1)

NAME

       Gyotoy - visualize one geodesic in Kerr metric

SYNOPSIS

       gyotoy [input.xml]

DESCRIPTION

       Gyoto is a framework for computing geodesics in curved space-times. The gyotoy utility program uses this framework to compute and display a
       single geodesic (the trajectory of a massive or mass-less particle) in Kerr metric.

       gyotoy takes as optional argument a scenery description in XML format (input.xml). This scenery must contain  a	Astrobj  section  of  kind
       Star. Alternatively, a default scenery is loaded.

       The  user  can then interactively select initial parameters and redraw the geodesic as many time as needed. the Projection parameters allow
       rotating the view and various menu entries are rather self-explanatory. Entries in the File menu allow saving the display as an image file,
       saving the parameters as an XML description, or saving the geodesic's coordinates in an ASCII file.

       gyotoy  is  only a small utility to visualise a single geodesic. It can also be invoked from the yorick(1) prompt for building more complex
       graphics and for scripting. Have a look at the gyoto.i and gyotoy.i files in yorick's Y_SITE directory.

       A companion program, gyoto(1), can be used to compute an entire Gyoto scenery using relativistic ray-tracing.

ENVIRONMENT

       GYOTO_PLUGINS
	      The "Star" object in Gyoto is part of the standard plug-in. If the GYOTO_PLUGINS environment variable is set,  it  must  contain	at
	      least "stdplug" for gyotoy to run properly.

AUTHOR

       Thibaut Paumard <thibaut.paumard@obspm.fr> wrote this manual.

SEE ALSO

       gyoto(1), yorick(1)

Science 							    AUGUST 2011 							 GYOTOY(1)