import math

import sys

R = 6378137.0 # meter

degreeToMeter = (R * math.pi / 180)

##

def earthDist(x1, y1, x2, y2):

# x = longitude

# y = latitude

dX = abs(x1-x2) * math.cos(y1)

dY = abs(y1-y2)

z = math.sqrt(dX*dX + dY*dY)

dist = z * degreeToMeter

print "dist=", dist

earthDist(127.1, 36.7, 127.2, 36.8)

earthDist(127.11, 36.71, 127.12, 36.72)

def earthDist2(dX, dY, midY):

dX = dX * math.cos(midY)

z = math.sqrt(dX*dX + dY*dY)

dist = z * degreeToMeter

print "dist=", dist

koreaX1 = 125 + (4/60.0) # 125:04

koreaX2 = 131 + (52/60.0) # 125:04

koreaY1 = 33 + (06/60.0) # 125:04

koreaY2 = 38 + (27/60.0) # 125:04

invalid = -1

class KoreaGrid:

def __init__(self, columns, rows):

self.numCols = columns

self.numRows = rows

self.stepX = (koreaX2 - koreaX1) / columns

self.stepY = (koreaY2 - koreaY1) / rows

self.maxRoomId = rows * columns - 1

self.roomRadius = earthDist2(self.stepX, self.stepY, koreaY2)

def info(self):

print "stepX=", self.stepX

print "stepY=", self.stepY

print "numRows=", self.numRows

print "numCols=", self.numCols

def getRoomId(self, x, y):

if x < koreaX1 or x > koreaX2 or y < koreaY1 or y > koreaY2:

return invalid

col = (x - koreaX1) / self.stepX

col = int(col)

row = (koreaY2 - y) / self.stepY

row = int(row)

id = row * self.numCols + col

print "x,y=",x,y,"\tid=", id

return id

def getNeighborRooms(self, room):

neighbors = []

neighbors.append(room-self.numCols-1)

neighbors.append(room-self.numCols)

neighbors.append(room-self.numCols+1)

neighbors.append(room-1)

neighbors.append(room)

neighbors.append(room+1)

neighbors.append(room+self.numCols-1)

neighbors.append(room+self.numCols)

neighbors.append(room+self.numCols+1)

if room % self.numCols == 0:

neighbors[0] = -1

neighbors[3] = -1

neighbors[6] = -1

if (room+1) % self.numCols == 0:

neighbors[2] = -1

neighbors[5] = -1

neighbors[8] = -1

for i in range(9):

if neighbors[i] > self.maxRoomId or neighbors[i] < 0:

neighbors[i] = -1

print

for i in range(3):

print "[%d] [%d] [%d]" % \

(neighbors[i*3], neighbors[i*3+1], neighbors[i*3+2])

grid = KoreaGrid(150, 200)

grid.info()

grid.getRoomId(127.5, 36.5)

grid.getRoomId(127.5, 36.6)

grid.getRoomId(127.6, 36.6)

grid.getNeighborRooms(0)

grid.getNeighborRooms(149)

grid.getNeighborRooms(150)

grid.getNeighborRooms(301)