Мне нравится этот код:
function getClientIP() {
if (isset($_SERVER)) {
if (isset($_SERVER["HTTP_X_FORWARDED_FOR"]))
return $_SERVER["HTTP_X_FORWARDED_FOR"];
if (isset($_SERVER["HTTP_CLIENT_IP"]))
return $_SERVER["HTTP_CLIENT_IP"];
return $_SERVER["REMOTE_ADDR"];
}
if (getenv('HTTP_X_FORWARDED_FOR'))
return getenv('HTTP_X_FORWARDED_FOR');
if (getenv('HTTP_CLIENT_IP'))
return getenv('HTTP_CLIENT_IP');
return getenv('REMOTE_ADDR');
}
Похищено прямо с http://www.cs.mun.ca/~rod/2500/notes/numpy-arrays/numpy-arrays.html
#
# line segment intersection using vectors
# see Computer Graphics by F.S. Hill
#
from numpy import *
def perp( a ) :
b = empty_like(a)
b[0] = -a[1]
b[1] = a[0]
return b
# line segment a given by endpoints a1, a2
# line segment b given by endpoints b1, b2
# return
def seg_intersect(a1,a2, b1,b2) :
da = a2-a1
db = b2-b1
dp = a1-b1
dap = perp(da)
denom = dot( dap, db)
num = dot( dap, dp )
return (num / denom.astype(float))*db + b1
p1 = array( [0.0, 0.0] )
p2 = array( [1.0, 0.0] )
p3 = array( [4.0, -5.0] )
p4 = array( [4.0, 2.0] )
print seg_intersect( p1,p2, p3,p4)
p1 = array( [2.0, 2.0] )
p2 = array( [4.0, 3.0] )
p3 = array( [6.0, 0.0] )
p4 = array( [6.0, 3.0] )
print seg_intersect( p1,p2, p3,p4)
class Point:
def __init__(self, x, y):
self.x = x
self.y = y
'''
finding intersect point of line AB and CD
where A is the first point of line AB
and B is the second point of line AB
and C is the first point of line CD
and D is the second point of line CD
'''
def get_intersect(A, B, C, D):
# a1x + b1y = c1
a1 = B.y - A.y
b1 = A.x - B.x
c1 = a1 * (A.x) + b1 * (A.y)
# a2x + b2y = c2
a2 = D.y - C.y
b2 = C.x - D.x
c2 = a2 * (C.x) + b2 * (C.y)
# determinant
det = a1 * b2 - a2 * b1
# parallel line
if det == 0:
return (float('inf'), float('inf'))
# intersect point(x,y)
x = ((b2 * c1) - (b1 * c2)) / det
y = ((a1 * c2) - (a2 * c1)) / det
return (x, y)