Flowdock
method

gamma

Importance_2
v1_9_1_378 - Show latest stable - 1 note - Class: Math
gamma(p1) public

Calculates the gamma function of x.

Note that gamma(n) is same as fact(n-1) for integer n >= 0. However gamma(n) returns float and possibly has error in calculation.

def fact(n) (1..n).inject(1) {|r,i| r*i } end 0.upto(25) {|i| p [i, Math.gamma(i+1), fact(i)] } #=>

0, 1.0, 1
1, 1.0, 1
2, 2.0, 2
3, 6.0, 6
4, 24.0, 24
5, 120.0, 120
6, 720.0, 720
7, 5040.0, 5040
8, 40320.0, 40320
9, 362880.0, 362880
10, 3628800.0, 3628800
11, 39916800.0, 39916800
12, 479001599.999999, 479001600
13, 6227020800.00001, 6227020800
14, 87178291199.9998, 87178291200
15, 1307674368000.0, 1307674368000
16, 20922789888000.0, 20922789888000
17, 3.55687428096001e+14, 355687428096000
18, 6.40237370572799e+15, 6402373705728000
19, 1.21645100408832e+17, 121645100408832000
20, 2.43290200817664e+18, 2432902008176640000
21, 5.10909421717094e+19, 51090942171709440000
22, 1.12400072777761e+21, 1124000727777607680000
23, 2.58520167388851e+22, 25852016738884976640000
24, 6.20448401733239e+23, 620448401733239439360000
25, 1.5511210043331e+25, 15511210043330985984000000
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May 15, 2012
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railz

heyyyy