Lua Attempt to call local 'callback' (a nil value)

[changx]

Hello! The first time I used lua, I encountered this mistake and didn't know how to solve it. Thank you for your help.
I used torch7 cudnn7 lua5.2
Here's my runtime error

/home/jm/torch/install/bin/lua: /home/jm/torch/install/share/lua/5.2/nn/Module.lua:352: attempt to call local 'callback' (a nil value)
stack traceback:
    /home/jm/torch/install/share/lua/5.2/nn/Module.lua:352: in function 'apply'
    ...nowflake/Downloads/CCX/seGAN/networks/End2EndNetwork.lua:81: in function 'defineG'
    ...nowflake/Downloads/CCX/seGAN/networks/End2EndNetwork.lua:130: in function 'init_networks'
    ...nowflake/Downloads/CCX/seGAN/networks/End2EndNetwork.lua:343: in main chunk
    [C]: in function 'dofile'
    /home/jm/torch/install/share/lua/5.2/paths/init.lua:84: in function 'dofile'
    main.lua:265: in main chunk
    [C]: in function 'dofile'
    ...cau2/torch/install/lib/luarocks/rocks/trepl/scm-1/bin/th:150: in main chunk
    [C]: in ?

And here's part of my code:

local function defineG(input_nc, output_nc, ngf)
    local netG = nil
    if     opt.which_model_netG == "encoder_decoder" then netG = defineG_encoder_decoder(input_nc, output_nc, ngf)
    elseif opt.which_model_netG == "unet" then netG = defineG_unet(input_nc, output_nc, ngf)
    elseif opt.which_model_netG == "unet_128" then netG = defineG_unet_128(input_nc, output_nc, ngf)
    else error("unsupported netG model")
    end

      netG:apply(weights_init)
 
    return netG
end

Is this a problem with the Lua version? Causing an error in the 'apply' function? But I don't know what to do. Thank you for your help.

 

[Infernum]

Where is weights_init defined? I'm assuming that's the callback that the apply method is trying to execute.

 

[changx]

Where is weights_init defined? I'm assuming that's the callback that the apply method is trying to execute.

Thank you very much! There's no weights_init in the code. I've redefined it and fixed this error!