prototorch_models/prototorch/models/extras.py
2021-11-15 11:43:39 +01:00

129 lines
3.6 KiB
Python

"""prototorch.models.extras
Modules not yet available in prototorch go here temporarily.
"""
import torch
from ..core.similarities import gaussian
def rank_scaled_gaussian(distances, lambd):
order = torch.argsort(distances, dim=1)
ranks = torch.argsort(order, dim=1)
return torch.exp(-torch.exp(-ranks / lambd) * distances)
def orthogonalization(tensors):
"""Orthogonalization via polar decomposition """
u, _, v = torch.svd(tensors, compute_uv=True)
u_shape = tuple(list(u.shape))
v_shape = tuple(list(v.shape))
# reshape to (num x N x M)
u = torch.reshape(u, (-1, u_shape[-2], u_shape[-1]))
v = torch.reshape(v, (-1, v_shape[-2], v_shape[-1]))
out = u @ v.permute([0, 2, 1])
out = torch.reshape(out, u_shape[:-1] + (v_shape[-2], ))
return out
def ltangent_distance(x, y, omegas):
r"""Localized Tangent distance.
Compute Orthogonal Complement: math:`\bm P_k = \bm I - \Omega_k \Omega_k^T`
Compute Tangent Distance: math:`{\| \bm P \bm x - \bm P_k \bm y_k \|}_2`
:param `torch.tensor` omegas: Three dimensional matrix
:rtype: `torch.tensor`
"""
x, y = [arr.view(arr.size(0), -1) for arr in (x, y)]
p = torch.eye(omegas.shape[-2], device=omegas.device) - torch.bmm(
omegas, omegas.permute([0, 2, 1]))
projected_x = x @ p
projected_y = torch.diagonal(y @ p).T
expanded_y = torch.unsqueeze(projected_y, dim=1)
batchwise_difference = expanded_y - projected_x
differences_squared = batchwise_difference**2
distances = torch.sqrt(torch.sum(differences_squared, dim=2))
distances = distances.permute(1, 0)
return distances
class GaussianPrior(torch.nn.Module):
def __init__(self, variance):
super().__init__()
self.variance = variance
def forward(self, distances):
return gaussian(distances, self.variance)
class RankScaledGaussianPrior(torch.nn.Module):
def __init__(self, lambd):
super().__init__()
self.lambd = lambd
def forward(self, distances):
return rank_scaled_gaussian(distances, self.lambd)
class ConnectionTopology(torch.nn.Module):
def __init__(self, agelimit, num_prototypes):
super().__init__()
self.agelimit = agelimit
self.num_prototypes = num_prototypes
self.cmat = torch.zeros((self.num_prototypes, self.num_prototypes))
self.age = torch.zeros_like(self.cmat)
def forward(self, d):
order = torch.argsort(d, dim=1)
for element in order:
i0, i1 = element[0], element[1]
self.cmat[i0][i1] = 1
self.cmat[i1][i0] = 1
self.age[i0][i1] = 0
self.age[i1][i0] = 0
self.age[i0][self.cmat[i0] == 1] += 1
self.age[i1][self.cmat[i1] == 1] += 1
self.cmat[i0][self.age[i0] > self.agelimit] = 0
self.cmat[i1][self.age[i1] > self.agelimit] = 0
def get_neighbors(self, position):
return torch.where(self.cmat[position])
def add_prototype(self):
new_cmat = torch.zeros([dim + 1 for dim in self.cmat.shape])
new_cmat[:-1, :-1] = self.cmat
self.cmat = new_cmat
new_age = torch.zeros([dim + 1 for dim in self.age.shape])
new_age[:-1, :-1] = self.age
self.age = new_age
def add_connection(self, a, b):
self.cmat[a][b] = 1
self.cmat[b][a] = 1
self.age[a][b] = 0
self.age[b][a] = 0
def remove_connection(self, a, b):
self.cmat[a][b] = 0
self.cmat[b][a] = 0
self.age[a][b] = 0
self.age[b][a] = 0
def extra_repr(self):
return f"(agelimit): ({self.agelimit})"