player distance monitor

blackList={
["Doc_Jason"]=true,
}
whiteList={
['darkbobo00']=true,
['dark_sjoerd']=true,
['Lekkerdie']=true,
['mastersnake20']=true,
['skye333']=true,
}

local pcX=-910
local pcZ=-1833
sensor=peripheral.wrap("left")
monitor=peripheral.wrap("back")


while true do
  local distances={}
  for name,__ in pairs(blackList) do
    data=sensor.getPlayerData(name)
    if data~=nil then
      local pos=data['position']
      local x=pos['x']
      local z=pos['z']
      x=math.floor(pcX+x+0.5)
      z=math.floor(pcZ+z+0.5)
      distance=math.floor(math.sqrt((x-pcX)^2+(z-pcZ)^2)+0.5)
      distances[name]={['x']=x,['z']=z,['d']=distance}
      print(name.." : "..x..","..z..","..distance)
    end
  end
  for name,__ in pairs(whiteList) do
    data=sensor.getPlayerData(name)
    if data~=nil then
      local pos=data['position']
      local x=pos['x']
      local z=pos['z']
      x=math.floor(pcX+x+0.5)
      z=math.floor(pcZ+z+0.5)
      distance=math.floor(math.sqrt((x-pcX)^2+(z-pcZ)^2)+0.5)
      distances[name]={['x']=x,['z']=z,['d']=distance}
      print(name.." : "..x..","..z..","..distance)
    end
  end

  local nameIndex=1
  local monitorX,monitorY=monitor.getSize()
  monitor.clear()
  for name,information in pairs(distances) do
    monitor.setCursorPos(1,nameIndex)
    local x=information['x']
    local z=information['z']
    local distance=information['d']
    if whiteList[name] then
        monitor.setTextColor(8192)
    elseif blackList[name] then
        monitor.setTextColor(16384)
    end
    name=string.sub(name,1,6)
    monitor.write(name..": "..x..","..z.."  Distance :"..distance)
    nameIndex=nameIndex+1
  end
  sleep(2)
end