File: math_extension_spec.rb

package info (click to toggle)
ruby-distribution 0.7.3%2Bdfsg-1
  • links: PTS, VCS
  • area: main
  • in suites: buster, stretch
  • size: 624 kB
  • ctags: 379
  • sloc: ruby: 4,283; makefile: 7
file content (281 lines) | stat: -rw-r--r-- 14,164 bytes parent folder | download | duplicates (2)
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
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
require File.expand_path(File.dirname(__FILE__)+"/spec_helper.rb")
include ExampleWithGSL
describe Distribution::MathExtension do
  it "binomial coefficient should be correctly calculated" do
    n=50
    n.times do |k|
      Math.binomial_coefficient(n,k).should eq(Math.factorial(n).quo(Math.factorial(k)*Math.factorial(n-k))),"not correct for k=#{k}"
    end
  end

  it "ChebyshevSeries for :sin should return correct values" do
    #Math::SIN_CS.evaluate()
  end

  it "log_1plusx_minusx should return correct values" do
    # Tests from GSL-1.9
    Math::Log.log_1plusx_minusx(1.0e-10).should be_within(1e-10).of(-4.999999999666666667e-21)
    Math::Log.log_1plusx_minusx(1.0e-8).should  be_within(1e-10).of(-4.999999966666666917e-17)
    Math::Log.log_1plusx_minusx(1.0e-4).should  be_within(1e-10).of(-4.999666691664666833e-09)
    Math::Log.log_1plusx_minusx(0.1).should     be_within(1e-10).of(-0.004689820195675139956)
    Math::Log.log_1plusx_minusx(0.49).should    be_within(1e-10).of(-0.09122388004263222704)

    Math::Log.log_1plusx_minusx(-0.49).should   be_within(1e-10).of(-0.18334455326376559639)
    Math::Log.log_1plusx_minusx(1.0).should     be_within(1e-10).of(Math::LN2 - 1.0)
    Math::Log.log_1plusx_minusx(-0.99).should   be_within(1e-10).of(-3.615170185988091368)
  end

  it "log_1plusx should return correct values" do
    # Tests from GSL-1.9
    Math::Log.log_1plusx(1.0e-10).should be_within(1e-10).of(9.999999999500000000e-11)
    Math::Log.log_1plusx(1.0e-8).should  be_within(1e-10).of(9.999999950000000333e-09)
    Math::Log.log_1plusx(1.0e-4).should  be_within(1e-10).of(0.00009999500033330833533)
    Math::Log.log_1plusx(0.1).should     be_within(1e-10).of(0.09531017980432486004)
    Math::Log.log_1plusx(0.49).should    be_within(1e-10).of(0.3987761199573677730)

    Math::Log.log_1plusx(-0.49).should   be_within(1e-10).of(-0.6733445532637655964)
    Math::Log.log_1plusx(1.0).should     be_within(1e-10).of(Math::LN2)
    Math::Log.log_1plusx(-0.99).should   be_within(1e-10).of(-4.605170185988091368)
  end

  it "log_beta should return correct values" do
    Math::Beta.log_beta(1.0e-8, 1.0e-8).first.should be_within(1e-10).of(19.113827924512310617)
    Math::Beta.log_beta(1.0e-8, 0.01).first.should be_within(1e-10).of(18.420681743788563403)
    Math::Beta.log_beta(1.0e-8, 1.0).first.should be_within(1e-10).of(18.420680743952365472)
    Math::Beta.log_beta(1.0e-8, 10.0).first.should be_within(1e-10).of(18.420680715662683009)
    Math::Beta.log_beta(1.0e-8, 1000.0).first.should be_within(1e-10).of(18.420680669107656949)
    Math::Beta.log_beta(0.1, 0.1).first.should be_within(1e-10).of(2.9813614810376273949)
    Math::Beta.log_beta(0.1, 1.0).first.should be_within(1e-10).of(2.3025850929940456840)
    Math::Beta.log_beta(0.1, 100.0).first.should be_within(1e-10).of(1.7926462324527931217)
    Math::Beta.log_beta(0.1, 1000).first.should be_within(1e-10).of(1.5619821298353164928)
    Math::Beta.log_beta(1.0, 1.00025).first.should be_within(1e-10).of(-0.0002499687552073570)
    Math::Beta.log_beta(1.0, 1.01).first.should be_within(1e-10).of(-0.009950330853168082848)
    Math::Beta.log_beta(1.0, 1000.0).first.should be_within(1e-10).of(-6.907755278982137052)
    Math::Beta.log_beta(100.0, 100.0).first.should be_within(1e-10).of(-139.66525908670663927)
    Math::Beta.log_beta(100.0, 1000.0).first.should be_within(1e-10).of(-336.4348576477366051)
    Math::Beta.log_beta(100.0, 1.0e+8).first.should be_within(1e-10).of(-1482.9339185256447309)
  end

  it "regularized_beta should return correct values" do
    Math.regularized_beta(0.0,1.0, 1.0).should be_within(1e-10).of(0.0)
    Math.regularized_beta(1.0, 1.0, 1.0).should be_within(1e-10).of(1.0)
    Math.regularized_beta(1.0, 0.1, 0.1).should be_within(1e-10).of(1.0)
    Math.regularized_beta(0.5, 1.0,  1.0).should be_within(1e-10).of(0.5)
    Math.regularized_beta(0.5, 0.1,  1.0).should be_within(1e-10).of(0.9330329915368074160)
    Math.regularized_beta(0.5, 10.0,  1.0).should be_within(1e-10).of(0.0009765625000000000000)
    Math.regularized_beta(0.5, 50.0,  1.0).should be_within(1e-10).of(8.881784197001252323e-16)
    Math.regularized_beta(0.5, 1.0,  0.1).should be_within(1e-10).of(0.06696700846319258402)
    Math.regularized_beta(0.5, 1.0, 10.0).should be_within(1e-10).of(0.99902343750000000000)
    Math.regularized_beta(0.5, 1.0, 50.0).should be_within(1e-10).of(0.99999999999999911180)
    Math.regularized_beta(0.1, 1.0,  1.0).should be_within(1e-10).of(0.10)
    Math.regularized_beta(0.1, 1.0,  2.0).should be_within(1e-10).of(0.19)
    Math.regularized_beta(0.9, 1.0,  2.0).should be_within(1e-10).of(0.99)
    Math.regularized_beta(0.5, 50.0, 60.0).should be_within(1e-10).of(0.8309072939016694143)
    Math.regularized_beta(0.5, 90.0, 90.0).should be_within(1e-10).of(0.5)
    Math.regularized_beta(0.5, 500.0,  500.0).should be_within(1e-10).of(0.5)
    Math.regularized_beta(0.4, 5000.0, 5000.0).should be_within(1e-10).of(4.518543727260666383e-91)
    Math.regularized_beta(0.6, 5000.0, 5000.0).should be_within(1e-10).of(1.0)
    Math.regularized_beta(0.6, 5000.0, 2000.0).should be_within(1e-10).of(8.445388773903332659e-89)
  end
  it_only_with_gsl "incomplete_beta should return correct values" do
    
    a=rand()*10+1
    b=rand()*10+1
    ib = GSL::Function.alloc { |t|  t**(a-1)*(1-t)**(b-1)}
    w = GSL::Integration::Workspace.alloc(1000)
    1.upto(10) {|x|
      inte=ib.qag([0,x / 10.0],w)
      Math.incomplete_beta(x/10.0, a ,b).should be_within(1e-10).of(inte[0])
    }
  end

  it "gammastar should return correct values" do
    # Tests from GSL-1.9
    Math::Gammastar.evaluate(1.0e-08).should        be_within(1e-10).of(3989.423555759890865)
    Math::Gammastar.evaluate(1.0e-05).should        be_within(1e-10).of(126.17168469882690233)
    Math::Gammastar.evaluate(0.001).should          be_within(1e-10).of(12.708492464364073506)
    Math::Gammastar.evaluate(1.5).should            be_within(1e-10).of(1.0563442442685598666)
    Math::Gammastar.evaluate(3.0).should            be_within(1e-10).of(1.0280645179187893045)
    Math::Gammastar.evaluate(9.0).should            be_within(1e-10).of(1.0092984264218189715)
    Math::Gammastar.evaluate(11.0).should           be_within(1e-10).of(1.0076024283104962850)
    Math::Gammastar.evaluate(100.0).should          be_within(1e-10).of(1.0008336778720121418)
    Math::Gammastar.evaluate(1.0e+05).should        be_within(1e-10).of(1.0000008333336805529)
    Math::Gammastar.evaluate(1.0e+20).should        be_within(1e-10).of(1.0)
  end

  it "erfc_e should return correct values" do
    # From GSL-1.9. For troubleshooting gammq.
    Math::erfc_e(-10.0).should be_within(1e-10).of(2.0)
    Math::erfc_e(-5.0000002).should be_within(1e-10).of(1.9999999999984625433)
    Math::erfc_e(-5.0).should be_within(1e-10).of(1.9999999999984625402)
    Math::erfc_e(-1.0).should be_within(1e-10).of(1.8427007929497148693)
    Math::erfc_e(-0.5).should be_within(1e-10).of(1.5204998778130465377)
    Math::erfc_e(1.0).should be_within(1e-10).of(0.15729920705028513066)
    Math::erfc_e(3.0).should be_within(1e-10).of(0.000022090496998585441373)
    Math::erfc_e(7.0).should be_within(1e-10).of(4.183825607779414399e-23)
    Math::erfc_e(10.0).should be_within(1e-10).of(2.0884875837625447570e-45)
  end


  it "unnormalized_incomplete_gamma with x=0 should return correct values" do
    Math.unnormalized_incomplete_gamma(-1.5, 0).should be_within(1e-10).of(4.0*Math.sqrt(Math::PI) / 3.0)
    Math.unnormalized_incomplete_gamma(-0.5, 0).should be_within(1e-10).of(-2*Math.sqrt(Math::PI))
    Math.unnormalized_incomplete_gamma(0.5, 0).should be_within(1e-10).of(Math.sqrt(Math::PI))
    Math.unnormalized_incomplete_gamma(1.0, 0).should eq 1.0
    Math.unnormalized_incomplete_gamma(1.5, 0).should be_within(1e-10).of(Math.sqrt(Math::PI) / 2.0)
    Math.unnormalized_incomplete_gamma(2.0, 0).should eq 1.0
    Math.unnormalized_incomplete_gamma(2.5, 0).should be_within(1e-10).of(0.75*Math.sqrt(Math::PI))
    
    Math.unnormalized_incomplete_gamma(3.0, 0).should be_within(1e-12).of(2.0)
    
    Math.unnormalized_incomplete_gamma(3.5, 0).should be_within(1e-10).of(15.0*Math.sqrt(Math::PI) / 8.0)
    Math.unnormalized_incomplete_gamma(4.0, 0).should be_within(1e-12).of(6.0)
  end

  it "incomplete_gamma should return correct values" do
    # Tests from GSL-1.9
    Math.incomplete_gamma(1e-100, 0.001).should be_within(1e-10).of(1.0)
    Math.incomplete_gamma(0.001, 0.001).should be_within(1e-10).of(0.9936876467088602902)
    Math.incomplete_gamma(0.001, 1.0).should be_within(1e-10).of(0.9997803916424144436)
    Math.incomplete_gamma(0.001, 10.0).should be_within(1e-10).of(0.9999999958306921828)
    Math.incomplete_gamma(1.0, 0.001).should be_within(1e-10).of(0.0009995001666250083319)
    Math.incomplete_gamma(1.0, 1.01).should be_within(1e-10).of(0.6357810204284766802)
    Math.incomplete_gamma(1.0, 10.0).should be_within(1e-10).of(0.9999546000702375151)
    Math.incomplete_gamma(10.0, 10.01).should be_within(1e-10).of(0.5433207586693410570)
    Math.incomplete_gamma(10.0, 20.0).should be_within(1e-10).of(0.9950045876916924128)
    Math.incomplete_gamma(1000.0, 1000.1).should be_within(1e-10).of(0.5054666401440661753)
    Math.incomplete_gamma(1000.0, 2000.0).should be_within(1e-10).of(1.0)

    # designed to trap the a-x=1 problem
    # These next two are 1e-7 because they give the same output as GSL, but GSL is apparently not totally accurate here.
    # It's a problem with log_1plusx_mx (log_1plusx_minusx in my code)
    Math.incomplete_gamma(100,  99.0).should be_within(1e-7).of(0.4733043303994607)
    Math.incomplete_gamma(200, 199.0).should be_within(1e-7).of(0.4811585880878718)

    # Test for x86 cancellation problems
    Math.incomplete_gamma(5670, 4574).should be_within(1e-10).of(3.063972328743934e-55)
  end

  it "gammq should return correct values" do
    # Tests from GSL-1.9
    Math.gammq(0.0, 0.001).should be_within(1e-10).of(0.0)
    Math.gammq(0.001, 0.001).should be_within(1e-10).of(0.006312353291139709793)
    Math.gammq(0.001, 1.0).should be_within(1e-10).of(0.00021960835758555639171)
    Math.gammq(0.001, 2.0).should be_within(1e-10).of(0.00004897691783098147880)
    Math.gammq(0.001, 5.0).should be_within(1e-10).of(1.1509813397308608541e-06)
    Math.gammq(1.0, 0.001).should be_within(1e-10).of(0.9990004998333749917)
    Math.gammq(1.0, 1.01).should be_within(1e-10).of(0.3642189795715233198)
    Math.gammq(1.0, 10.0).should be_within(1e-10).of(0.00004539992976248485154)
    Math.gammq(10.0, 10.01).should be_within(1e-10).of(0.4566792413306589430)
    Math.gammq(10.0, 100.0).should be_within(1e-10).of(1.1253473960842733885e-31)
    Math.gammq(1000.0, 1000.1).should be_within(1e-10).of(0.4945333598559338247)
    Math.gammq(1000.0, 2000.0).should be_within(1e-10).of(6.847349459614753180e-136)

    # designed to trap the a-x=1 problem
    Math.gammq(100,  99.0).should be_within(1e-10).of(0.5266956696005394)
    Math.gammq(200, 199.0).should be_within(1e-10).of(0.5188414119121281)
  
    # Test for x86 cancellation problems
    Math.gammq(5670, 4574).should be_within(1e-10).of(1.0000000000000000)


    # test suggested by Michel Lespinasse [gsl-discuss Sat, 13 Nov 2004]
    Math.gammq(1.0e+06-1.0, 1.0e+06-2.0).should be_within(1e-10).of(0.50026596175224547004)

    # tests in asymptotic regime related to Lespinasse test
    Math.gammq(1.0e+06+2.0, 1.0e+06+1.0).should be_within(1e-10).of(0.50026596135330304336)
    Math.gammq(1.0e+06, 1.0e+06-2.0).should be_within(1e-10).of(0.50066490399940144811)
    Math.gammq(1.0e+07, 1.0e+07-2.0).should be_within(1e-10).of(0.50021026104978614908)
  end


  it "rising_factorial should return correct values" do
    
    x=rand(10)+1
    Math.rising_factorial(x,0).should eq 1
    Math.rising_factorial(x,1).should eq x
    Math.rising_factorial(x,2).should eq x**2+x
    Math.rising_factorial(x,3).should eq x**3+3*x**2+2*x
    Math.rising_factorial(x,4).should eq x**4+6*x**3+11*x**2+6*x

  end
  
  it "permutations should return correct values" do
    n=rand(50)+50
    10.times { |k|
      Math.permutations(n,k).should eq(Math.factorial(n) / Math.factorial(n-k))
    }
    
    
    Math.permutations(n,n).should eq(Math.factorial(n) / Math.factorial(n-n))
  end
  
  
  it "exact regularized incomplete beta should behave properly" do

    Math.exact_regularized_beta(0.5,5,5).should be_within(1e-6).of(0.5)
    Math.exact_regularized_beta(0.5,5,6).should be_within(1e-6).of(0.6230469)
    Math.exact_regularized_beta(0.5,5,7).should  be_within(1e-6).of(0.725586)
    
    a=5
    b=5
    Math.exact_regularized_beta(0,a,b).should eq 0
    Math.exact_regularized_beta(1,a,b).should eq 1
    x=rand()
    
    Math.exact_regularized_beta(x,a,b).should be_within(1e-6). of(1-Math.regularized_beta(1-x,b,a))
    
    
  end
  
  it "binomial coefficient(gamma) with n<=48 should be correct " do
    
    [1,5,10,25,48].each {|n|
      k=(n/2).to_i
      Math.binomial_coefficient_gamma(n,k).round.should eq(Math.binomial_coefficient(n,k))
    }
  end
  
  it "binomial coefficient(gamma) with 48<n<1000 should have 11 correct digits" do 
    
    [50,100,200,1000].each {|n|
      k=(n/2).to_i
      obs=Math.binomial_coefficient_gamma(n, k).to_i.to_s[0,11]
      exp=Math.binomial_coefficient(n, k).to_i.to_s[0,11]
      
      obs.should eq(exp)
    }
  end
  
  describe Distribution::MathExtension::SwingFactorial do

    it "Math.factorial should return correct values x<20" do
      ac=3628800 # 10!
      11.upto(19).each do |i|
        ac*=i
        Math.factorial(i).should eq(ac)
      end
    end
    
    it "Math.factorial should return correct values for values 21<x<33" do
      
      ac=2432902008176640000 # 20!
      21.upto(33).each do |i|
        ac*=i
        Math.factorial(i).should eq(ac)
      end
      
    end
    
    it "Math.factorial should return correct values for values x>33" do
      
      ac=8683317618811886495518194401280000000 # 33!
      Math.factorial(33).should eq ac
      34.upto(40).each do |i|
        ac*=i
        Math.factorial(i).should eq(ac)
      end
    
    end
  end
end