def make_environment(images, labels, e):
'''
https://github.com/facebookresearch/InvariantRiskMinimization
'''
# different from the IRM repo, here the labels are already binarized
images = images.reshape((-1, 28, 28))
# change label with prob 0.25
prob_label = torch.ones((10, 10)).float() * (0.25 / 9)
for i in range(10):
prob_label[i, i] = 0.75
labels_prob = torch.index_select(prob_label, dim=0, index=labels)
labels = Categorical(probs=labels_prob).sample()
# assign the color variable
prob_color = torch.ones((10, 10)).float() * (e / 9.0)
for i in range(10):
prob_color[i, i] = 1 - e
color_prob = torch.index_select(prob_color, dim=0, index=labels)
color = Categorical(probs=color_prob).sample()
# Apply the color to the image by zeroing out the other color channel
output_images = torch.zeros((len(images), 10, 28, 28))
idx_dict = defaultdict(list)
for i in range(len(images)):
idx_dict[int(labels[i])].append(i)
output_images[i, color[i], :, :] = images[i]
cor = color.float()
idx_list = list(range(len(images)))
return {
'images': (output_images.float() / 255.),
'labels': labels.long(),
'idx_dict': idx_dict,
'idx_list': idx_list,
'cor': cor,
}
def forward(self, decoder_output, mode='train'):
ret = self.fc(decoder_output)
if self.hard or mode != 'train':
# apply temperature, do softmax
command = self.identity(
ret[..., :self.command_len]) / self.mix_temperature
command_max = torch.max(command, dim=-1, keepdim=True)[0]
command = torch.exp(command - command_max)
command = command / torch.sum(command, dim=-1, keepdim=True)
# sample from the given probs, this is the same as get_pi_idx
# and already returns not soft prob
# [seq_len, batch, command_len]
command = Categorical(probs=command).sample()
# [seq_len, batch]
command = F.one_hot(command, self.command_len).to(
decoder_output.device).float()
# print(command.size())
arguments = ret[..., self.command_len:]
# args are [seq_len, batch, 6*3*num_mix], and get [seq_len*batch*6, 3*num_mix]
arguments = arguments.reshape([-1, 3 * self.num_mix])
mdn_coef = self.get_mdn_coef(arguments)
out_logmix, out_mean, out_logstd = mdn_coef['logmix'], mdn_coef[
'mean'], mdn_coef['logstd']
# these are [seq_len*batch*6, num_mix]
# apply temp to logmix
out_logmix = self.identity(out_logmix) / self.mix_temperature
out_logmix_max = torch.max(out_logmix, dim=-1, keepdim=True)[0]
out_logmix = torch.exp(out_logmix - out_logmix_max)
out_logmix = out_logmix / torch.sum(
out_logmix, dim=-1, keepdim=True)
# get_pi_idx
out_logmix = Categorical(probs=out_logmix).sample()
# [seq_len*batch*arg_len]
out_logmix = out_logmix.long().unsqueeze(1)
out_logmix = torch.cat([
torch.arange(out_logmix.size(0),
device=decoder_output.device).unsqueeze(1),
out_logmix
],
dim=-1)
# [seq_len*batch*arg_len, 2]
chosen_mean = [out_mean[i[0], i[1]] for i in out_logmix]
chosen_logstd = [out_logstd[i[0], i[1]] for i in out_logmix]
chosen_mean = torch.tensor(chosen_mean,
device=decoder_output.device)
chosen_logstd = torch.tensor(chosen_logstd,
device=decoder_output.device)
rand_gaussian = (
torch.randn(chosen_mean.size(), device=decoder_output.device) *
math.sqrt(self.gauss_temperature))
arguments = chosen_mean + torch.exp(chosen_logstd) * rand_gaussian
batch_size = command.size(1)
arguments = arguments.reshape(
-1, batch_size, self.arg_len) # [seg_len, batch, arg_len]
# concat with the command we picked
ret = torch.cat([command, arguments], dim=-1)
return ret
