Source code for geotorch.skew

import torch
from torch import nn
from .exceptions import VectorError, NonSquareError

[docs]class Skew(nn.Module): def __init__(self, lower=True): r""" Vector space of skew-symmetric matrices, parametrized in terms of the upper or lower triangular part of a matrix. Args: size (torch.size): Size of the tensor to be parametrized lower (bool): Optional. Uses the lower triangular part of the matrix to parametrize the matrix. Default: ``True`` """ super().__init__() self.lower = lower @staticmethod def frame(X, lower): if lower: X = X.tril(-1) else: X = X.triu(1) return X - X.transpose(-2, -1) def forward(self, X): if len(X.size()) < 2: raise VectorError(type(self).__name__, X.size()) if X.size(-2) != X.size(-1): raise NonSquareError(type(self).__name__, X.size()) return self.frame(X, self.lower)
[docs] @staticmethod def in_manifold(X): return ( X.dim() >= 2 and X.size(-2) == X.size(-1) and torch.allclose(X, -X.transpose(-2, -1)) )