common.lua

require 'torch'
require 'xlua'
require 'sys'

function sameSize(a, b)
   if a:nDimension() ~= b:nDimension() then
      return false
   else
      local sa = a:size()
      local sb = b:size()
      for i = 1,#sa do
	 if sa[i] ~= sb[i] then
	    return false
	 end
      end
      return true
   end
end

function flownorm(flow)
   return (flow[1]:clone():cmul(flow[1]) + flow[2]:clone():cmul(flow[2])):sqrt()
end

function round(x)
   return math.floor(x+0.5)
end

function modProgress(i, max, mod)
   if math.mod(i, mod) == 0 then
      xlua.progress(i, max)
   end
end

function randInt(a, b) --a included, b excluded
   return math.floor(torch.uniform(a, b))
end

function randomPermutation(n)
   local ret = torch.Tensor(n)
   for i = 1,n do
      local rnd = randInt(1, i+1)
      ret[i] = ret[rnd]
      ret[rnd] = i
   end
   return ret
end

-- Get the median of a table.
function median(t)
  local temp={}

  -- deep copy table so that when we sort it, the original is unchanged
  -- also weed out any non numbers
  for k,v in pairs(t) do
    if type(v) == 'number' then
      table.insert( temp, v )
    end
 end

  if (#temp == 0) then
     print("error: median : empty table")
  end

  table.sort( temp )

  -- If we have an even number of table elements or odd.
  if math.fmod(#temp,2) == 0 then
    -- return mean value of middle two elements
    return ( temp[#temp/2] + temp[(#temp/2)+1] ) / 2
  else
    -- return middle elements
    return temp[math.ceil(#temp/2)]
  end
end

function split(str, char)
   local nb, ne
   local e = 0
   ret = {}
   while true do
      nb, ne = str:find(char, e+1)
      if nb == nil then
	 table.insert(ret, str:sub(e+1))
	 return ret
      end
      table.insert(ret, str:sub(e+1, nb-1))
      e = ne
   end
end

function strip(str, chars)
   if type(chars) == 'string' then chars = {chars} end
   assert(type(chars) == 'table')
   local function nochar(a)
      for i = 1,#chars do
	 if a == chars[i] then
	    return false
	 end
      end
      return true
   end
   local i = 1
   while i <= str:len() do
      if nochar(str:sub(i,i)) then
	 break
      end
      i = i+1
   end
   local str2 = str:sub(i)
   i = str2:len()
   while i >= 1 do
      if nochar(str2:sub(i,i)) then
	 break
      end
      i = i-1
   end
   return str2:sub(1,i)
end

function ls2(dir, filter)
   local ls = split(sys.execute('ls ' .. dir), '\n')
   local ret = {}
   for i = 1,#ls do
      local a = strip(ls[i],{' '})
      if a ~= '' then
	 if filter then
	    if filter(a) then
	       table.insert(ret, a)
	    end
	 else
	    table.insert(ret, a)
	 end
      end
   end
   return ret
end

function lsR(dir, filter, dirfilter, return_dir_filter)
   if dir:sub(-1) ~= '/' then dir = dir..'/' end
   local ls = split(sys.execute('ls -d '.. dir .. '*/ 2> /dev/null' ), '\n')
   local ret = {}
   for i = 1,#ls do
      local a = strip(ls[i], {' '})
      if a ~= '' then
	 if a:sub(-1) == '/' then
	    local sub = {}
	    if dirfilter then
	       if dirfilter(a) then
		  sub = lsR(a, filter, dirfilter, return_dir_filter)
		  if return_dir_filter then
		     if return_dir_filter(a) then table.insert(ret, a) end
		  end
	       end
	    else
	       sub = lsR(a, filter, dirfilter, return_dir_filter)
	       if return_dir_filter then
		  if return_dir_filter(a) then table.insert(ret, a) end
	       end
	    end
	    for j = 1,#sub do
	       table.insert(ret, sub[j])
	    end
	 end
      end
   end
   local lsf = split(sys.execute("ls -ld ".. dir .. "* | grep -v ^d"), '\n')
   for i = 1,#lsf do
      local a = strip(lsf[i], {' '})
      if a ~= '' then
	 a = split(a, ' ')
	 a = a[#a]
	 if filter then
	    if filter(a) then
	       table.insert(ret, a)
	    end
	 else
	    table.insert(ret, a)
	 end
      end
   end
   return ret
end

function isdir(path)
   local a = sys.execute('if [ -d '..path..' ]; then echo 1; else echo 0; fi')
   return a:sub(1,1) == '1'
end