code: def integrate_dxdv(self,dxdv,t,pot,method='dopr54_c',
                         rectIn=False,rectOut=False):
          
          pot= flatten_potential(pot)
          _check_potential_dim(self,pot)
          _check_consistent_units(self,pot)
          # Parse t
          if _APY_LOADED and isinstance(t,units.Quantity):
              self._orb._integrate_t_asQuantity= True
              t= t.to(units.Gyr).value\
                  /bovy_conversion.time_in_Gyr(self._vo,self._ro)
          self._orb.integrate_dxdv(dxdv,t,pot,method=method,
                                   rectIn=rectIn,rectOut=rectOut)
docs: NAME:
  
             integrate_dxdv
  
          PURPOSE:
  
             integrate the orbit and a small area of phase space
  
          INPUT:
  
             dxdv - [dR,dvR,dvT,dphi]
  
             t - list of times at which to output (0 has to be in this!) (can be Quantity)
  
             pot - potential instance or list of instances
  
             method= 'odeint' for scipy's odeint
  
                     'rk4_c' for a 4th-order Runge-Kutta integrator in C
  
                     'rk6_c' for a 6-th order Runge-Kutta integrator in C
  
                     'dopr54_c' for a Dormand-Prince integrator in C (generally the fastest)
  
                     'dopr54_c' is recommended, odeint is *not* recommended
  
  
             rectIn= (False) if True, input dxdv is in rectangular coordinates
  
             rectOut= (False) if True, output dxdv (that in orbit_dxdv) is in rectangular coordinates
  
          OUTPUT:
  
             (none) (get the actual orbit using getOrbit_dxdv(), the orbit that is integrated alongside with dxdv is stored as usual, any previous regular orbit integration will be erased!)
  
          HISTORY:
  
             2010-10-17 - Written - Bovy (IAS)
  
             2014-06-29 - Added rectIn and rectOut - Bovy (IAS)