The semitorus command creates a three-dimensional plot data object, which when displayed is a section of the torus centered at [x,y,z], whose meridian has radius r and distance from the center of a meridian to the center of the semitorus is R.  The semitorus starts at radian angle a and ends at radian angle b.

A call to semitorus produces a plot data object, which can be used in a PLOT3D data structure, or displayed using the plots[display] command.

Remaining arguments are interpreted as options, which are specified as equations of the form option = value. For more information, see plottools and plot3d/options.

$\mathrm{with}\left(\mathrm{plottools}\right)\:$

$\mathrm{with}\left(\mathrm{plots}\right)\:$

$\mathrm{display}\left(\mathrm{semitorus}\left(\left[1\,1\,1\right]\,0..\frac{\mathrm{\pi }}{2}\,2\,7\right)\,\mathrm{lightmodel}=\mathrm{light4}\,\mathrm{orientation}=\left[-140\,60\right]\,\mathrm{scaling}=\mathrm{constrained}\,\mathrm{style}=\mathrm{surface}\right)$