Torchx - Error while creating train.t7 and test.t7 files using custom data set

[syamprasadkr]

I am trying to feed my own dataset to the CNN model I created and I am using torchx to do this. The code to create the training and testing .t7 files is uploaded here.

I tested this code by creating a train_set.t7 of 5000 images and test_set.t7 of 500 images. Everything went well and I was able to load the images to the CNN model. Then I tried creating another set of .t7 files from a larger dataset. I would like to explain a bit about the organization of the dataset. There is a ROOT folder called data (in the code, look for ROOT). There are two sub folders in it: train and test. Each of these sub folders are divided into 5 different folders named: 1, 2, 3, 4 and 5. Each of these folders have around 70,000 images in the case of train.

The problem is that my code throws the following error after adding all the files from data/train/1:

/home/ubuntu/torch/install/bin/luajit: ...e/ubuntu/torch/install/share/lua/5.1/torchx/indexdir.lua:53: attempt to perform arithmetic on a nil value
stack traceback:
   ...e/ubuntu/torch/install/share/lua/5.1/torchx/indexdir.lua:53: in function 'indexdir'
   create_t7.lua:25: in main chunk
   [C]: in function 'dofile'
   ...untu/torch/install/lib/luarocks/rocks/trepl/scm-1/bin/th:150: in main chunk
   [C]: at 0x0000cff9

I tried changing the order of folders, but it didn't help. What does this error indicate? Thanks in advance.