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
|
require File.expand_path(File.dirname(__FILE__)+"/spec_helper.rb")
describe Distribution::Logistic do
shared_examples_for "logistic engine" do
it "should return correct pdf" do
if @engine.respond_to? :pdf
1.upto(10) {
u=rand()
s=rand()+1
x=rand()*100-50
exp=Math.exp(-(x-u) / s) / (s*(1+Math.exp(-(x-u) / s)**2))
@engine.pdf(x,u,s).should eq(exp)
}
else
pending("No #{@engine}.pdf")
end
end
it "should return correct cdf" do
if @engine.respond_to? :cdf
1.upto(100) {
u=rand()
s=rand()*100
x=rand()*100-50
exp=1/(1+Math.exp(-(x-u) / s))
@engine.cdf(x,u,s).should eq(exp)
}
else
pending("No #{@engine}.cdf")
end
end
it "should return correct p_value" do
if @engine.respond_to? :p_value
1.upto(9) {|i|
u=rand()
s=rand()*100
x=@engine.p_value(i/10.0,u,s)
@engine.cdf(x,u,s).should be_within(1e-10).of(i/10.0)
}
else
pending("No #{@engine}.cdf")
end
end
end
describe "singleton" do
before do
@engine=Distribution::Logistic
end
it_should_behave_like "logistic engine"
end
describe Distribution::Logistic::Ruby_ do
before do
@engine=Distribution::Logistic::Ruby_
end
it_should_behave_like "logistic engine"
end
end
|