fix a bug in DCGAN (pytorch#121)

Using single GPU in DCGAN caused an error because 'gpu_ids' in forward function will be None .

Author: huqinghao

dcgan/main.py

@@ -129,7 +129,7 @@ def __init__(self, ngpu):
 
  def forward(self, input):
  gpu_ids = None
- if isinstance(input.data, torch.cuda.FloatTensor) and self.ngpu > 1:
+ if isinstance(input.data, torch.cuda.FloatTensor) and self.ngpu >= 1:
  gpu_ids = range(self.ngpu)
  return nn.parallel.data_parallel(self.main, input, gpu_ids)
 
@@ -168,7 +168,7 @@ def __init__(self, ngpu):
 
  def forward(self, input):
  gpu_ids = None
- if isinstance(input.data, torch.cuda.FloatTensor) and self.ngpu > 1:
+ if isinstance(input.data, torch.cuda.FloatTensor) and self.ngpu > =1:
  gpu_ids = range(self.ngpu)
  output = nn.parallel.data_parallel(self.main, input, gpu_ids)
  return output.view(-1, 1)