1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
|
#!/usr/bin/env ruby
items = [0, 1, 2]
ranks = [1, 2, 3]
#permutations = [
# [1,2,3],
# [2,3,1],
# [3,1,2],
# [3,2,1],
# [1,3,2]
#]
scores = [3, 2, 1]
def f items, ranks, scores,topone=false
prod = 1
items.each_with_index { |i,j|
x = []
d = Math.exp(scores[ranks[i]-1])
x << ranks[i]
sum = 0
if j+1 <= items.size
(j).upto(items.size-1) { |k|
sum = sum+Math.exp(scores[ranks[k]-1])
x << ranks[k]
}
prod = prod*(d/sum)
if topone
return prod
end
puts "#{ranks[i]} / #{x[1..-1].map { |z| "#{z}" }.join(" ")}"
end
}
return prod
end
#best = f items,ranks,scores
permutations = {}
sz = 0
stop = 0
while true
break if stop == 1000
r = ranks.shuffle
permutations[r] = 1
if sz == permutations.size
stop = stop+1
else
sz = permutations.size
stop = 0
end
end
puts permutations.to_s
sumtoone = 0
permutations.each_key { |r|
p = f items,r,scores,false
puts "#{r.to_s} #{p}"
puts
sumtoone = sumtoone+p
#if p >= best
# puts r.to_s
# puts p
#end
}
puts "==="
puts sumtoone
puts "+++ NLL"
scores = [0.1,0.1,100]
true_ranking = [2,1,3]
puts(-Math.log(f(items,true_ranking,scores)))
|
