Bug encountered When running Google's Deep Q Network Code - lua

Question

Google's Deep Q Network for Atari Games is here.
https://github.com/rahular/deepmind-dqn
When I run it with GPU setting
./run_gpu <game name>
I had this error
../torch/bin/luajit: ./convnet.lua:22: attempt to call local 'convLayer' (a nil value)
stack traceback:
./convnet.lua:22: in function 'network'
./NeuralQLearner.lua:89: in function '__init'
...einforcement_Learning/torch/share/lua/5.1/torch/init.lua:51: in function <...einforcement_Learning/torch/share/lua/5.1/torch/init.lua:47>
[C]: at 0x7f419423d380
./initenv.lua:133: in function 'setup'
train_agent.lua:52: in main chunk
[C]: at 0x00406230
The code that caused this issue is in this file https://github.com/rahular/deepmind-dqn/blob/master/dqn/convnet.lua
and it is in this function
function create_network(args)
local net = nn.Sequential()
net:add(nn.Reshape(unpack(args.input_dims)))
--- first convolutional layer
local convLayer = nn.SpatialConvolution
if args.gpu >= 0 then
net:add(nn.Transpose({1,2},{2,3},{3,4}))
convLayer = nn.SpatialConvolutionCUDA
end
net:add(convLayer(args.hist_len*args.ncols, args.n_units[1],
args.filter_size[1], args.filter_size[1],
args.filter_stride[1], args.filter_stride[1],1))
net:add(args.nl())
The net:add(convLayer( is 22th line.
I used gpu setting so it seems
convLayer = nn.SpatialConvolutionCUDA
caused convLayer to be nil.
Does anyone know why nn.SpatialConvolutionCUDA returns a nil ?

Answer 1

Did the code originally come with GPU support, or did you add it yourself?
You should replaced the depreceated layers, i.e. replace:
net:add(nn.Transpose({1,2},{2,3},{3,4}))
convLayer = nn.SpatialConvolutionCUDA
with
convLayer = nn.SpatialConvolution
Check the documentation for the layers.
Edit: Use this branch, I fixed it for GPU support.

Answer 2

Found the solution.
using this github branch
https://github.com/soumith/deepmind-atari
After cloning this branch, then install cutorch and cunn using luarocks.
Now you can run the code.