(self, inv_method=None)
return self._rhs
Returns the system's equations of motion in first order form.

        The output of this will be the right hand side of:

        [qdot, udot].T = f(q, u, t)

        Or, the equations of motion in first order form.  The right hand side
        is what is needed by most numerical ODE integrators.

        Parameters
        ==========

        inv_method : str
            The specific sympy inverse matrix calculation method to use. For a
            list of valid methods, see :py:method:
            `~sympy.matrices.matrices.MatrixBase.inv`
Returns the system's equations of motion in first order form.
Returns the system s equations of motion in first order form .
def rhs(self, inv_method=None):
        """ Returns the system's equations of motion in first order form.

        The output of this will be the right hand side of:

        [qdot, udot].T = f(q, u, t)

        Or, the equations of motion in first order form.  The right hand side
        is what is needed by most numerical ODE integrators.

        Parameters
        ==========

        inv_method : str
            The specific sympy inverse matrix calculation method to use. For a
            list of valid methods, see :py:method:
            `~sympy.matrices.matrices.MatrixBase.inv`

        """
        if inv_method is None:
            self._rhs = _mat_inv_mul(self.mass_matrix_full,
                                          self.forcing_full)
        else:
            self._rhs = (self.mass_matrix_full.inv(inv_method,
                         try_block_diag=True) * self.forcing_full)
        return self._rhs
def rhs ( self , inv_method = None ) : if inv_method is None : self . _rhs = _mat_inv_mul ( self . mass_matrix_full , self . forcing_full ) else : self . _rhs = ( self . mass_matrix_full . inv ( inv_method , try_block_diag = True ) * self . forcing_full ) return self . _rhs