attempt to call method 'adjustForData' (a nil value)

[ProGamerGov]

ubuntu@ip-Address:~/neural-style$ th test.lua
test
/home/ubuntu/torch/install/bin/luajit: /home/ubuntu/torch/install/share/lua/5.1/hdf5/group.lua:97: attempt to call method 'adjustForData' (a nil value)
stack traceback:
        /home/ubuntu/torch/install/share/lua/5.1/hdf5/group.lua:97: in function '_writeData'
        /home/ubuntu/torch/install/share/lua/5.1/hdf5/group.lua:307: in function '_write_or_append'
        /home/ubuntu/torch/install/share/lua/5.1/hdf5/group.lua:270: in function </home/ubuntu/torch/install/share/lua/5.1/hdf5/group.lua:269>
        /home/ubuntu/torch/install/share/lua/5.1/hdf5/file.lua:84: in function '_write_or_append'
        /home/ubuntu/torch/install/share/lua/5.1/hdf5/file.lua:58: in function 'write'

This is where the error occurs:

for i = 1, #input_images_caffe do
   newFile:write('images', input_images_caffe[i], 'w')
end

The images inside input_image_caffe, come from:

  local input_size = math.ceil(params.input_scale * params.image_size)
  local input_image_list = params.input_image:split(',')
  local input_images_caffe = {}
  local img_caffe
  for _, img_path in ipairs(input_image_list) do
    local img = image.load(img_path, 3)
    img = image.scale(img, input_size, 'bilinear')
    img_caffe = preprocess(img):float()
    table.insert(input_images_caffe, img_caffe)
  end

function preprocess(img)
  local mean_pixel = torch.DoubleTensor({103.939, 116.779, 123.68})
  local perm = torch.LongTensor{3, 2, 1}
  img = img:index(1, perm):mul(256.0)
  mean_pixel = mean_pixel:view(3, 1, 1):expandAs(img)
  img:add(-1, mean_pixel)
  return img
end

I am not sure why this issue is occurring, or how to fix it.

[ProGamerGov]

Some examples of what input_images_caffe could contain:

{
  1 : FloatTensor - size: 3x405x512
  2 : FloatTensor - size: 3x512x393
}

{
  1 : FloatTensor - size: 3x405x512
}

I used this to create the HDF5 file:

local newFile = hdf5.open(params.output_hdf5, 'w')

[ProGamerGov]

So it turns out that you only need 'w' for creating the HDF5 file.

Removing the 'w' resolved the issue:

newFile:write('images', input_images_caffe[i])