forked from clbustos/distribution
/
exponential_spec.rb
89 lines (81 loc) · 2.28 KB
/
exponential_spec.rb
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
76
77
78
79
80
81
82
83
84
85
86
87
88
89
require File.expand_path(File.dirname(__FILE__) + '/spec_helper.rb')
describe Distribution::Exponential do
shared_examples_for 'exponential engine' do
it 'should return correct pdf' do
if @engine.respond_to? :pdf
[0.5, 1, 1.5].each {|l|
1.upto(5) {|x|
expect(@engine.pdf(x, l)).to be_within(1e-10).of(l * Math.exp(-l * x))
}
}
else
pending("No #{@engine}.pdf")
end
end
it 'should return correct cdf' do
if @engine.respond_to? :cdf
[0.5, 1, 1.5].each {|l|
1.upto(5) {|x|
expect(@engine.cdf(x, l)).to be_within(1e-10).of(1 - Math.exp(-l * x))
}
}
else
pending("No #{@engine}.cdf")
end
end
it 'should return correct p_value' do
if @engine.respond_to? :p_value
[0.5, 1, 1.5].each {|l|
1.upto(5) {|x|
pr = @engine.cdf(x, l)
expect(@engine.p_value(pr, l)).to be_within(1e-10).of(x)
}
}
else
pending("No #{@engine}.p_value")
end
end
end
describe 'singleton' do
before do
@engine = Distribution::Exponential
end
it_should_behave_like 'exponential engine'
end
describe Distribution::Exponential::Ruby_ do
before do
@engine = Distribution::Exponential::Ruby_
end
it_should_behave_like 'exponential engine'
end
if Distribution.has_gsl?
describe Distribution::Exponential::GSL_ do
before do
@engine = Distribution::Exponential::GSL_
end
it_should_behave_like 'exponential engine'
end
end
# if Distribution.has_java?
# describe Distribution::Exponential::Java_ do
# before do
# @engine=Distribution::Exponential::Java_
# end
# it_should_behave_like "exponential engine"
#
# end
# end
describe 'rng' do
it 'should default to Kernel#rand if no :random is given' do
allow(Random).to receive(:rand).and_return(0.5)
rng = Distribution::Exponential.rng 1.0
rng.call
end
it 'should use a given rng if one is passed during construction' do
random = double('random')
allow(random).to receive(:rand).and_return(0.5)
rng = Distribution::Exponential.rng 1.0, random: random
rng.call
end
end
end