class menpofit.differentiable.DL[source]

Bases: object

Object that is able to take its own derivative with respect to landmark changes.

abstract d_dl(points)[source]

The derivative of this spatial object with respect to spatial changes in anchor landmark points or centres, evaluated at points.


points ((n_points, n_dims) ndarray) – The spatial points at which the derivative should be evaluated.


d_dl ((n_points, n_centres, n_dims) ndarray) – The Jacobian wrt landmark changes.

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

Note that at present this assumes that the change in every dimension is equal.