Hamiltonian

The Hamiltonian is given by

$H(q,p,t)=\dot{q_i}{p}_i-L(q,\dot{q},t)$

where $q_i$ are the generalised coordinates, $p_i$ are the canonical momentum, and L is the Lagrangian. Using the Hamiltonian function, the equations of motion can be expressed in the so-called canonical form:

$\dot{p_i}=-\frac{\partial H}{\partial q_i}$

and

$\dot{q_i}=\frac{\partial H}{\partial p_i}$