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Quan (Andy) Gan 70695ff8f8 [Model] Training GraphSAGE with PyTorch Lightning (#2878)
* pytorch lightning initial examples

* revert most changes in dataloader to favor #2886.

* address comments
2021-05-11 11:28:13 +08:00

20 行
647 B
Python

import torch as th
import dgl
class NegativeSampler(object):
def __init__(self, g, k, neg_share=False):
self.weights = g.in_degrees().float() ** 0.75
self.k = k
self.neg_share = neg_share
def __call__(self, g, eids):
src, _ = g.find_edges(eids)
n = len(src)
if self.neg_share and n % self.k == 0:
dst = self.weights.multinomial(n, replacement=True)
dst = dst.view(-1, 1, self.k).expand(-1, self.k, -1).flatten()
else:
dst = self.weights.multinomial(n*self.k, replacement=True)
src = src.repeat_interleave(self.k)
return src, dst