function clear()
 term.setBackgroundColor(colors.black)
 term.setTextColor(colors.white)
 term.setCursorPos(1,1)
 term.clear()
end

function line(x,y)
 local cX,cY = term.getCursorPos()
 term.setBackgroundColor(colors.black)
 term.setTextColor(colors.white)
 term.setCursorPos(cX+x,cY+y)
end

function comma(amount)
 local formatted = amount
 while true do
  formatted, k = string.gsub(formatted, "^(-?%d+)(%d%d%d)", '%1,%2')
  if (k==0) then
   break
  end
 end
 return formatted
end

function round(num, numDecimalPlaces)
  local mult = 10^(numDecimalPlaces or 0)
  return math.floor(num * mult + 0.5) / mult
end