agnets</a> have a curved reference orbit.
For both rectangular and sector bending magnets
<p>
<img align=bottom src="../equations/RSbend.gif">
<p>
where alphais the bend angle.
A positive bend angle represents a bend to the right,
i.e. towards negative <i>x</i> values.
For sector bending magnets,
the bend radius is given by rho,
and for rectangular bending magnets it has the value
<p>
rho = <i>L</i> / 2 sin(alpha/2).
<p>
If the magnet is rotated about the <i>s</i>-axis by an angle psi,
<i>R</i> and <i>S</i>