1#!/usr/bin/perl -w
2
3# Test blog function (and bpow, since it uses blog).
4
5# It is too slow to be simple included in bigfltpm.inc, where it would get
6# executed 3 times. One time would be under BareCalc, which shouldn't make any
7# difference since there is no CALC->_log() function, and one time under a
8# subclass, which *should* work.
9
10# But it is better to test the numerical functionality, instead of not testing
11# it at all (which did lead to wrong answers for 0 < $x < 1 in blog() in
12# versions up to v1.63, and for bsqrt($x) when $x << 1 for instance).
13
14use Test;
15use strict;
16
17BEGIN
18  {
19  $| = 1;
20  # to locate the testing files
21  my $location = $0; $location =~ s/biglog.t//i;
22  if ($ENV{PERL_CORE})
23    {
24    # testing with the core distribution
25    @INC = qw(../lib);
26    }
27  unshift @INC, '../lib';
28  if (-d 't')
29    {
30    chdir 't';
31    require File::Spec;
32    unshift @INC, File::Spec->catdir(File::Spec->updir, $location);
33    }
34  else
35    {
36    unshift @INC, $location;
37    }
38  print "# INC = @INC\n";
39
40  plan tests => 53;
41  }
42
43use Math::BigFloat;
44use Math::BigInt;
45
46my $cl = "Math::BigFloat";
47
48# These tests are now really fast, since they collapse to blog(10), basically
49# Don't attempt to run them with older versions. You are warned.
50
51# $x < 0 => NaN
52ok ($cl->new(-2)->blog(), 'NaN');
53ok ($cl->new(-1)->blog(), 'NaN');
54ok ($cl->new(-10)->blog(), 'NaN');
55ok ($cl->new(-2,2)->blog(), 'NaN');
56
57my $ten = $cl->new(10)->blog();
58
59# 10 is cached (up to 75 digits)
60ok ($cl->new(10)->blog(), '2.302585092994045684017991454684364207601');
61
62# 0.1 is using the cached value for log(10), too
63
64ok ($cl->new(0.1)->blog(), -$ten);
65ok ($cl->new(0.01)->blog(), -$ten * 2);
66ok ($cl->new(0.001)->blog(), -$ten * 3);
67ok ($cl->new(0.0001)->blog(), -$ten * 4);
68
69# also cached
70ok ($cl->new(2)->blog(), '0.6931471805599453094172321214581765680755');
71ok ($cl->new(4)->blog(), $cl->new(2)->blog * 2);
72
73# These are still slow, so do them only to 10 digits
74
75ok ($cl->new('0.2')->blog(undef,10), '-1.609437912');
76ok ($cl->new('0.3')->blog(undef,10), '-1.203972804');
77ok ($cl->new('0.4')->blog(undef,10), '-0.9162907319');
78ok ($cl->new('0.5')->blog(undef,10), '-0.6931471806');
79ok ($cl->new('0.6')->blog(undef,10), '-0.5108256238');
80ok ($cl->new('0.7')->blog(undef,10), '-0.3566749439');
81ok ($cl->new('0.8')->blog(undef,10), '-0.2231435513');
82ok ($cl->new('0.9')->blog(undef,10), '-0.1053605157');
83
84ok ($cl->new('9')->blog(undef,10), '2.197224577');
85
86ok ($cl->new('10')->blog(10,10),   '1.000000000');
87ok ($cl->new('20')->blog(20,10),   '1.000000000');
88ok ($cl->new('100')->blog(100,10), '1.000000000');
89
90ok ($cl->new('100')->blog(10,10),  '2.000000000');	# 10 ** 2 == 100
91ok ($cl->new('400')->blog(20,10),  '2.000000000');	# 20 ** 2 == 400
92
93ok ($cl->new('4')->blog(2,10),  '2.000000000');		# 2 ** 2 == 4
94ok ($cl->new('16')->blog(2,10), '4.000000000');		# 2 ** 4 == 16
95
96ok ($cl->new('1.2')->bpow('0.3',10),  '1.056219968');	
97ok ($cl->new('10')->bpow('0.6',10),   '3.981071706');
98
99# blog should handle bigint input
100ok (Math::BigFloat::blog(Math::BigInt->new(100),10), 2);
101
102# some integer results
103ok ($cl->new(2)->bpow(32)->blog(2),  '32');	# 2 ** 32
104ok ($cl->new(3)->bpow(32)->blog(3),  '32');	# 3 ** 32
105ok ($cl->new(2)->bpow(65)->blog(2),  '65');	# 2 ** 65
106
107# test for bug in bsqrt() not taking negative _e into account
108test_bpow ('200','0.5',10,      '14.14213562');
109test_bpow ('20','0.5',10,       '4.472135955');
110test_bpow ('2','0.5',10,        '1.414213562');
111test_bpow ('0.2','0.5',10,      '0.4472135955');
112test_bpow ('0.02','0.5',10,     '0.1414213562');
113test_bpow ('0.49','0.5',undef , '0.7');
114test_bpow ('0.49','0.5',10 ,    '0.7000000000');
115test_bpow ('0.002','0.5',10,    '0.04472135955');
116test_bpow ('0.0002','0.5',10,   '0.01414213562');
117test_bpow ('0.0049','0.5',undef,'0.07');
118test_bpow ('0.0049','0.5',10 ,  '0.07000000000');
119test_bpow ('0.000002','0.5',10, '0.001414213562');
120test_bpow ('0.021','0.5',10,    '0.1449137675');
121test_bpow ('1.2','0.5',10,      '1.095445115');
122test_bpow ('1.23','0.5',10,     '1.109053651');
123test_bpow ('12.3','0.5',10,     '3.507135583');
124
125test_bpow ('9.9','0.5',10,        '3.146426545');
126test_bpow ('9.86902225','0.5',10, '3.141500000');
127test_bpow ('9.86902225','0.5',undef, '3.1415');
128
129test_bpow ('0.2','0.41',10,   '0.5169187652');
130
131sub test_bpow
132  {
133  my ($x,$y,$scale,$result) = @_;
134
135  print "# Tried: $x->bpow($y,$scale);\n"
136   unless ok ($cl->new($x)->bpow($y,$scale),$result);
137  }
138
139