This data item defines a cylindrical segment in space.
Other data items can check if nodes are located on this geometry.
The coordinate of the center point at the
bottom is *x_0 y_0 z_0*. The coordinate of the center point at the
top is *x_1 y_1 z_1*.
If *side_x* is set to a positive value, say +1.,
then only x-values larger then *x_c* are considered
to be part of the geometry.
If *side_y* is set to a negative value, say -1.,
then only x-values smaller then *x_c* are considered
to be part of the geometry.
If *side_x* is set to 0 ,
then all x-values are considered
to be part of the geometry.
Likewise remarks hold for y- and z-values.
The cylinder segment can only be used in 3D.
All **node** within a distance *tolerance* of the radius
are considered to be part of the cylinder.