kane.py 文件源码

def _coords(self, qind, qdep=[], coneqs=[]):
        """Supply all the generalized coordinates in a list.

        If some coordinates are dependent, supply them as part of qdep. Their
        dependent nature will only show up in the linearization process though.

        Parameters
        ==========

        qind : list
            A list of independent generalized coords
        qdep : list
            List of dependent coordinates
        coneq : list
            List of expressions which are equal to zero; these are the
            configuration constraint equations
        """

        if not isinstance(qind, (list, tuple)):
            raise TypeError('Generalized coords. must be supplied in a list.')
        self._q = qind + qdep
        self._qdot = [diff(i, dynamicsymbols._t) for i in self._q]

        if not isinstance(qdep, (list, tuple)):
            raise TypeError('Dependent coordinates and constraints must each be '
                            'provided in their own list.')
        if len(qdep) != len(coneqs):
            raise ValueError('There must be an equal number of dependent '
                             'coordinates and constraints.')
        coneqs = Matrix(coneqs)
        self._qdep = qdep
        self._f_h = coneqs