DX

class menpo.base.DX

Bases: object

Object that is able to take it’s own derivative wrt spatial changes.

d_dx(points)

The first order derivative of this spatial object wrt spatial changes evaluated at points.

Parameters:

points : (n_points, n_dims) ndarray

The spatial points at which the derivative should be evaluated.

Returns:

d_dx : (n_points, n_dims, n_dims) ndarray

The jacobian wrt spatial changes.

d_dx[i, j, k] is the scalar differential change that the j’th dimension of the i’th point experiences due to a first order change in the k’th dimension.

It may be the case that the jacobian is constant across space - in this case axis zero may have length 1 to allow for broadcasting.