attempt to index field 'transitions' (a nil value) stack traceback:

[Yashashree Jadhav]

Hello,

Kindly help me out. I am beginner in the field deep reinforcement learning. Also Torch/LuaJit is very new to me.

These days I am trying to implement my own code to control mobile robot path. I want to prepare basic program and want to test it on my robot. So I can clearly understand DQN performance in real environment.

I used Torch/LuaJit for implementation.I have also used ros interface for robot interaction. My receiver program is ROS supportive cpp program and it receives data (webcam output) from camera sensor and extract images. I want feed this images to my agent.

Currently I am using some random (robot path) images and  I feed this images to my agent​ program through perceive function (once preprocessing done). My agent program can successfully received this data.

But it has given me following error

qlua: ./Agent.lua:246: attempt to index field 'transitions' (a nil value)
stack traceback:
[C]: in function '__index'
./Agent.lua:246: in function 'perceive'
imagepreprocessing.lua:80: in main chunk

I have attached source file. Your guidance will be helpful for me.

Thank you and Regards,
Yashashree