import math

def LonLatToPixelXY(lonlat):
  (lon, lat) = lonlat
  x = (lon + 180.0) * 256.0 / 360.0
  y = 128.0 - math.log(math.tan((lat + 90.0) * math.pi / 360.0)) * 128.0 / math.pi
  return [x, y]