Symbolic integrator for OCPs
============================

The integrator class can be used in conjunction with *trajectory
optimization*, where the symbolic primitives can be passed for initial
state, control inputs, initial and final time and parameters. 
This can be embedded in an optimization
problem and solved for the optimal control input vector. See examples from Larson
and Kelly notebook where single and multiple shooting is implemented.

.. code:: python

    sym_dict=get_symbols(n_x=1,n_u=1,n_p=0,N=10)
    t=sym_dict['t']
    u=sym_dict['u']
    f=2*t+u
    _=scale_ode(sym_dict=sym_dict,f=f)
    _=integrator(sym_dict=sym_dict,options=None)
    x0=cs.DM([0])
    t0,tf=cs.MX.sym('t0',1,1),cs.MX.sym('tf',1,1)
    u=cs.MX.sym('u',1,10)
    simulate(t0=t0,tf=tf,x0=x0,u=u,sym_dict=sym_dict)