Error when using dropout in GRU

[Trojahn]

The following toy example works:

require 'rnn'

model = nn.Sequential()
model:add(nn.GRU(10, 5, 20))
model:add(nn.GRU(5, 1, 20))
model:add(nn.Sigmoid())
model = nn.Sequencer(model)

t = torch.Tensor(20,10)
model:forward(t)
print(model.output)

But using the available dropout parameter don't:

require 'rnn'

model = nn.Sequential()
model:add(nn.GRU(10, 5, 20, 0.25))
model:add(nn.GRU(5, 1, 20))
model:add(nn.Sigmoid())
model = nn.Sequencer(model)

t = torch.Tensor(20,10)
model:forward(t)
print(model.output)

The error itself...
In 1 module of nn.Sequential:
In 1 module of nn.Sequential:
In 2 module of nn.ConcatTable:
In 1 module of nn.Sequential:
In 1 module of nn.ParallelTable:
In 3 module of nn.Sequential:
bad argument #2 to '?' (out of bounds at /tmp/luarocks_torch-scm-1-9229/torch7/lib/TH/generic/THStorage.c:202)
...

[tastyminerals]

Check your input to the model, it is probably one dimensional but should be two dimensional.