How to use the pygeodesy.fmath.fdot function in PyGeodesy

           @return: New, rotated vector (L{Vector3d}).

           @JSname: I{rotateAround}.
        '''
        a = self.others(axis, name='axis').unit()  # axis being rotated around

        c = cos(theta)
        b = a.times(1 - c)
        s = a.times(sin(theta))

        p = self.unit().xyz  # point being rotated

        # multiply p by a quaternion-derived rotation matrix
        return self.classof(fdot(p, a.x * b.x + c,   a.x * b.y - s.z, a.x * b.z + s.y),
                            fdot(p, a.y * b.x + s.z, a.y * b.y + c,   a.y * b.z - s.x),
                            fdot(p, a.z * b.x - s.y, a.z * b.y + s.x, a.z * b.z + c))

           @arg theta: The angle of rotation (C{radians}).

           @return: New, rotated vector (L{Vector3d}).

           @JSname: I{rotateAround}.
        '''
        a = self.others(axis, name='axis').unit()  # axis being rotated around

        c = cos(theta)
        b = a.times(1 - c)
        s = a.times(sin(theta))

        p = self.unit().xyz  # point being rotated

        # multiply p by a quaternion-derived rotation matrix
        return self.classof(fdot(p, a.x * b.x + c,   a.x * b.y - s.z, a.x * b.z + s.y),
                            fdot(p, a.y * b.x + s.z, a.y * b.y + c,   a.y * b.z - s.x),
                            fdot(p, a.z * b.x - s.y, a.z * b.y + s.x, a.z * b.z + c))

'''(INTERNAL) Compute the 4-, 6- or 8-th order Krüger Alpha
           or Beta series coefficients per Karney 2011, 'Transverse
           Mercator with an accuracy of a few nanometers', U{page 7,
           equations 35 and 36}.

           @arg AB8Ks: 8-Tuple of 8-th order Krüger Alpha or Beta series
                       coefficient tuples.

           @return: Krüger series coefficients (C{.KsOrder}-tuple).

           @see: The 30-th order U{TMseries30
                 }.
        '''
        k = self.KsOrder
        ns = fpowers(self.n, k)
        return tuple(fdot(AB8Ks[i][:k-i], *ns[i:]) for i in range(k))

           @arg xyz: Local C{(x, y, z)} coordinates (C{3-tuple}).
           @arg xyz0: Optional, local C{(x0, y0, z0)} origin (C{3-tuple}).

           @return: Unrotated C{(x, y, z)} location (C{3-tuple}).
        '''
        if xyz0:
            if len(xyz0) != len(xyz):
                raise LenError(self.unrotate, xyz0=len(xyz0), xyz=len(xyz))

            _xyz = (1.0,) + xyz
            # x' = x0 + M[0] * x + M[1] * y + M[2] * z
            # y' = y0 + M[3] * x + M[4] * y + M[5] * z
            # z' = z0 + M[6] * x + M[7] * y + M[8] * z
            xyz_ = (fdot(_xyz, xyz0[0], *self[0:3]),
                    fdot(_xyz, xyz0[1], *self[3:6]),
                    fdot(_xyz, xyz0[2], *self[6:]))
        else:
            # x' = M[0] * x + M[1] * y + M[2] * z
            # y' = M[3] * x + M[4] * y + M[5] * z
            # z' = M[6] * x + M[7] * y + M[8] * z
            xyz_ = (fdot(xyz, *self[0:3]),
                    fdot(xyz, *self[3:6]),
                    fdot(xyz, *self[6:]))
        return xyz_

           @arg y: Y coordinate (C{meter}).
           @arg z: Z coordinate (C{meter}).
           @kwarg inverse: Optional direction, forward or inverse (C{bool}).

           @return: A L{Vector3Tuple}C{(x, y, z)}, transformed.
        '''
        if inverse:
            _xyz = -1, -x, -y, -z
            _s1 = self.s1 - 2  # == -(1 - s * 1e-6)) == -(1 - (s1 - 1))
        else:
            _xyz =  1,  x,  y,  z
            _s1  = self.s1
        # x', y', z' = (.tx + x * .s1 - y * .rz + z * .ry,
        #               .ty + x * .rz + y * .s1 - z * .rx,
        #               .tz - x * .ry + y * .rx + z * .s1)
        r = Vector3Tuple(fdot(_xyz, self.tx,      _s1, -self.rz,  self.ry),
                         fdot(_xyz, self.ty,  self.rz,      _s1, -self.rx),
                         fdot(_xyz, self.tz, -self.ry,  self.rx,      _s1))
        return self._xnamed(r)

s = E.e2s2(sa)  # r, v = E.roc2_(sa, _F0)
        v = a_F0 / sqrt(s)  # nu
        r = v * E.e12 / s  # rho = a_F0 * E.e12 / pow(s, 1.5) == a_F0 * E.e12 / (s * sqrt(s))

        vr = v / r  # == s / E.e12
        x2 = vr - 1  # η2
        ta = tan(a)

        v3, v5, v7 = fpowers(v, 7, 3)  # PYCHOK false!
        ta2, ta4, ta6 = fpowers(ta**2, 3)  # PYCHOK false!

        tar = ta / r
        V4 = (a,
              tar / (  2 * v),
              tar / ( 24 * v3) * fdot((1, 3, -9), 5 + x2, ta2, ta2 * x2),
              tar / (720 * v5) * fdot((61, 90, 45), 1, ta2, ta4))

        csa = 1.0 / ca
        X5 = (_B0,
              csa / v,
              csa / (   6 * v3) * fsum_(vr, ta2, ta2),
              csa / ( 120 * v5) * fdot((5, 28, 24), 1, ta2, ta4),
              csa / (5040 * v7) * fdot((61, 662, 1320, 720), 1, ta2, ta4, ta6))

        d, d2, d3, d4, d5, d6, d7 = fpowers(e - _E0, 7)  # PYCHOK false!
        a = fdot(V4, 1,    -d2, d4, -d6)
        b = fdot(X5, 1, d, -d3, d5, -d7)

        self._latlon = _LLEB(degrees90(a), degrees180(b), datum=self.datum, name=self.name)
        return self._latlon3(LatLon, datum)

tar = ta / r
        V4 = (a,
              tar / (  2 * v),
              tar / ( 24 * v3) * fdot((1, 3, -9), 5 + x2, ta2, ta2 * x2),
              tar / (720 * v5) * fdot((61, 90, 45), 1, ta2, ta4))

        csa = 1.0 / ca
        X5 = (_B0,
              csa / v,
              csa / (   6 * v3) * fsum_(vr, ta2, ta2),
              csa / ( 120 * v5) * fdot((5, 28, 24), 1, ta2, ta4),
              csa / (5040 * v7) * fdot((61, 662, 1320, 720), 1, ta2, ta4, ta6))

        d, d2, d3, d4, d5, d6, d7 = fpowers(e - _E0, 7)  # PYCHOK false!
        a = fdot(V4, 1,    -d2, d4, -d6)
        b = fdot(X5, 1, d, -d3, d5, -d7)

        self._latlon = _LLEB(degrees90(a), degrees180(b), datum=self.datum, name=self.name)
        return self._latlon3(LatLon, datum)

v3, v5, v7 = fpowers(v, 7, 3)  # PYCHOK false!
        ta2, ta4, ta6 = fpowers(ta**2, 3)  # PYCHOK false!

        tar = ta / r
        V4 = (a,
              tar / (  2 * v),
              tar / ( 24 * v3) * fdot((1, 3, -9), 5 + x2, ta2, ta2 * x2),
              tar / (720 * v5) * fdot((61, 90, 45), 1, ta2, ta4))

        csa = 1.0 / ca
        X5 = (_B0,
              csa / v,
              csa / (   6 * v3) * fsum_(vr, ta2, ta2),
              csa / ( 120 * v5) * fdot((5, 28, 24), 1, ta2, ta4),
              csa / (5040 * v7) * fdot((61, 662, 1320, 720), 1, ta2, ta4, ta6))

        d, d2, d3, d4, d5, d6, d7 = fpowers(e - _E0, 7)  # PYCHOK false!
        a = fdot(V4, 1,    -d2, d4, -d6)
        b = fdot(X5, 1, d, -d3, d5, -d7)

        self._latlon = _LLEB(degrees90(a), degrees180(b), datum=self.datum, name=self.name)
        return self._latlon3(LatLon, datum)

ta2, ta4 = fpowers(ta, 4, 2)  # PYCHOK false!

    vsa = v * sa
    I4 = (E.b * _F0 * _M(E.Mabcd, a) + _N0,
         (vsa /   2) * ca,
         (vsa /  24) * ca3 * fsum_(5, -ta2, 9 * x2),
         (vsa / 720) * ca5 * fsum_(61, ta4, -58 * ta2))

    V4 = (_E0,
         (v        * ca),
         (v /   6) * ca3 * (r - ta2),
         (v / 120) * ca5 * fdot((-18, 1, 14, -58), ta2, 5 + ta4, x2, ta2 * x2))

    d, d2, d3, d4, d5, d6 = fpowers(b - _B0, 6)  # PYCHOK false!
    n = fdot(I4, 1, d2, d4, d6)
    e = fdot(V4, 1, d,  d3, d5)

    if Osgr is None:
        r = _EasNor2Tuple(e, n)
    else:
        r = Osgr(e, n, datum=_Datums_OSGB36, **Osgr_kwds)
        if lon is None and isinstance(latlon, _LLEB):
            r._latlon = latlon  # XXX weakref(latlon)?
    return _xnamed(r, name)