def ptransp()

in hype/manifolds/lorentz.py [0:0]

• 18 lines of code
• 4 McCabe index (conditional complexity)

    def ptransp(self, x, y, v, ix=None, out=None):
        """Parallel transport for hyperboloid"""
        if ix is not None:
            v_ = v
            x_ = x.index_select(0, ix)
            y_ = y.index_select(0, ix)
        elif v.is_sparse:
            ix, v_ = v._indices().squeeze(), v._values()
            x_ = x.index_select(0, ix)
            y_ = y.index_select(0, ix)
        else:
            raise NotImplementedError
        xy = self.ldot(x_, y_, keepdim=True).expand_as(x_)
        vy = self.ldot(v_, y_, keepdim=True).expand_as(x_)
        vnew = v_ + vy / (1 - xy) * (x_ + y_)
        if out is None:
            return vnew
        else:
            out.index_copy_(0, ix, vnew)