Segmentation fault at model at step model:forward() in lua file format

[SUNNY TIWARI]

require 'torch'   -- torch

require 'optim'

require 'nn'      -- provides a normalization operator

function string:split(sep)

  local sep, fields = sep, {}

  local pattern = string.format("([^%s]+)", sep)

  self:gsub(pattern, function(substr) fields[#fields + 1] = substr end)

  return fields

end

local f_file = io.open(arg[1], 'r')

local p_file = io.open(arg[2], 'w')

local data = torch.Tensor(1, 351)

local name = ''

for line in f_file:lines('*l') do

local l = line:split(',')

first = true

for key, val in ipairs(l) do

  if first == false then

  data[1][key] = val

  else data[1][key] = 0

  first = false

  name = val

  end

end

end

local X = data[{{},{2,-1}}]

local model = torch.load('estimation_model.dat')

print("2")

local myPrediction = model:forward(X)

p_file:write('NAME,F1,F2,F3,F4\n')

p_file:write(name..','..tostring(1000*myPrediction[1][1])..','..tostring(1000*myPrediction[1][2])..','..tostring(1000*myPrediction[1][3])..','..tostring(1000*myPrediction[1][4])..'\n')

I am getting segmentation fault(core dumped at line shown in bold above.