(self, reference_frame, second_reference_frame=None)
return Matrix([i.dot(self).dot(j) for i in reference_frame for j in
                      second_reference_frame]).reshape(3, 3)
Returns the matrix form of the dyadic with respect to one or two
        reference frames.

        Parameters
        ----------
        reference_frame : ReferenceFrame
            The reference frame that the rows and columns of the matrix
            correspond to. If a second reference frame is provided, this
            only corresponds to the rows of the matrix.
        second_reference_frame : ReferenceFrame, optional, default=None
            The reference frame that the columns of the matrix correspond
            to.

        Returns
        -------
        matrix : ImmutableMatrix, shape(3,3)
            The matrix that gives the 2D tensor form.

        Examples
        --------

        >>> from sympy import symbols
        >>> from sympy.physics.vector import ReferenceFrame, Vector
        >>> Vector.simp = True
        >>> from sympy.physics.mechanics import inertia
        >>> Ixx, Iyy, Izz, Ixy, Iyz, Ixz = symbols('Ixx, Iyy, Izz, Ixy, Iyz, Ixz')
        >>> N = ReferenceFrame('N')
        >>> inertia_dyadic = inertia(N, Ixx, Iyy, Izz, Ixy, Iyz, Ixz)
        >>> inertia_dyadic.to_matrix(N)
        Matrix([
        [Ixx, Ixy, Ixz],
        [Ixy, Iyy, Iyz],
        [Ixz, Iyz, Izz]])
        >>> beta = symbols('beta')
        >>> A = N.orientnew('A', 'Axis', (beta, N.x))
        >>> inertia_dyadic.to_matrix(A)
        Matrix([
        [                           Ixx,                                           Ixy*cos(beta) + Ixz*sin(beta),                                           -Ixy*sin(beta) + Ixz*cos(beta)],
        [ Ixy*cos(beta) + Ixz*sin(beta), Iyy*cos(2*beta)/2 + Iyy/2 + Iyz*sin(2*beta) - Izz*cos(2*beta)/2 + Izz/2,                 -Iyy*sin(2*beta)/2 + Iyz*cos(2*beta) + Izz*sin(2*beta)/2],
        [-Ixy*sin(beta) + Ixz*cos(beta),                -Iyy*sin(2*beta)/2 + Iyz*cos(2*beta) + Izz*sin(2*beta)/2, -Iyy*cos(2*beta)/2 + Iyy/2 - Iyz*sin(2*beta) + Izz*cos(2*beta)/2 + Izz/2]])
Returns the matrix form of the dyadic with respect to one or two
        reference frames.
Returns the matrix form of the dyadic with respect to one or two reference frames .
def to_matrix(self, reference_frame, second_reference_frame=None):
        """Returns the matrix form of the dyadic with respect to one or two
        reference frames.

        Parameters
        ----------
        reference_frame : ReferenceFrame
            The reference frame that the rows and columns of the matrix
            correspond to. If a second reference frame is provided, this
            only corresponds to the rows of the matrix.
        second_reference_frame : ReferenceFrame, optional, default=None
            The reference frame that the columns of the matrix correspond
            to.

        Returns
        -------
        matrix : ImmutableMatrix, shape(3,3)
            The matrix that gives the 2D tensor form.

        Examples
        --------

        >>> from sympy import symbols
        >>> from sympy.physics.vector import ReferenceFrame, Vector
        >>> Vector.simp = True
        >>> from sympy.physics.mechanics import inertia
        >>> Ixx, Iyy, Izz, Ixy, Iyz, Ixz = symbols('Ixx, Iyy, Izz, Ixy, Iyz, Ixz')
        >>> N = ReferenceFrame('N')
        >>> inertia_dyadic = inertia(N, Ixx, Iyy, Izz, Ixy, Iyz, Ixz)
        >>> inertia_dyadic.to_matrix(N)
        Matrix([
        [Ixx, Ixy, Ixz],
        [Ixy, Iyy, Iyz],
        [Ixz, Iyz, Izz]])
        >>> beta = symbols('beta')
        >>> A = N.orientnew('A', 'Axis', (beta, N.x))
        >>> inertia_dyadic.to_matrix(A)
        Matrix([
        [                           Ixx,                                           Ixy*cos(beta) + Ixz*sin(beta),                                           -Ixy*sin(beta) + Ixz*cos(beta)],
        [ Ixy*cos(beta) + Ixz*sin(beta), Iyy*cos(2*beta)/2 + Iyy/2 + Iyz*sin(2*beta) - Izz*cos(2*beta)/2 + Izz/2,                 -Iyy*sin(2*beta)/2 + Iyz*cos(2*beta) + Izz*sin(2*beta)/2],
        [-Ixy*sin(beta) + Ixz*cos(beta),                -Iyy*sin(2*beta)/2 + Iyz*cos(2*beta) + Izz*sin(2*beta)/2, -Iyy*cos(2*beta)/2 + Iyy/2 - Iyz*sin(2*beta) + Izz*cos(2*beta)/2 + Izz/2]])

        """

        if second_reference_frame is None:
            second_reference_frame = reference_frame

        return Matrix([i.dot(self).dot(j) for i in reference_frame for j in
                      second_reference_frame]).reshape(3, 3)
def to_matrix ( self , reference_frame , second_reference_frame = None ) : if second_reference_frame is None : second_reference_frame = reference_frame return Matrix ( [ i . dot ( self ) . dot ( j ) for i in reference_frame for j in second_reference_frame ] ) . reshape ( 3 , 3 )