Given multiple (x,y) ordered pairs, I want to compare distances between each one of them. So pretend I have a list of ordered pairs:
pairs = [a,b,c,d,e,f]
I have a function that takes two ordered pairs and find the distance between them:
def distance(a,b):
from math import sqrt as sqrt
from math import pow as pow
d1 = pow((a[0] - b[0]),2)
d2 = pow((a[1] - b[1]),2)
distance = sqrt(d1 + d2)
return distance
How can I use this function to compare every ordered pair to every other ordered pair, ultimately finding the two ordered-pairs with the greatest distance between them?
Psuedopsuedocode:
distance(a,b)
distance(a,c)
...
distance(e,f)
Any help would be tremendously appreciated.
try:
from itertools import combinations
except ImportError:
def combinations(l, n):
if n != 2: raise Exception('This placeholder only good for n=2')
for i in range(len(l)):
for j in range(i+1, len(l)):
yield l[i], l[j]
coords_list = [(0,0), (3,4), (6,8)]
def distance(p1, p2):
return ( ( p2[0]-p1[0] ) ** 2 + ( p2[1]-p1[1] )**2 ) ** 0.5
largest_distance, (p1, p2) = max([
(distance(p1,p2), (p1, p2)) for (p1,p2) in combinations(coords_list, 2)
])
print largest_distance, p1, p2