#!/usr/bin/env python

"""
Pairwise distance module for pytorch.
"""

import torch.autograd as autograd
import torch.nn as nn

class PairwiseDistance(nn.Module):
    def __init__(self, norm_type, dim=1):
        super(PairwiseDistance, self).__init__()
        self.norm_type = norm_type
        self.dim = dim

    def forward(self, input):
        return autograd.variable.Norm(self.norm_type,
                                      self.dim)(input[1]-input[0])