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
|
#!/usr/bin/perl -w
# Copyright 2012, 2013 Kevin Ryde
# This file is part of Math-PlanePath.
#
# Math-PlanePath is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by the Free
# Software Foundation; either version 3, or (at your option) any later
# version.
#
# Math-PlanePath is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
# or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
# for more details.
#
# You should have received a copy of the GNU General Public License along
# with Math-PlanePath. If not, see <http://www.gnu.org/licenses/>.
use 5.004;
use strict;
use Test;
plan tests => 3;
use lib 't','xt';
use MyTestHelpers;
BEGIN { MyTestHelpers::nowarnings(); }
use MyOEIS;
use Math::PlanePath::DigitGroups;
# uncomment this to run the ### lines
#use Smart::Comments '###';
#------------------------------------------------------------------------------
# parity_bitwise() vs path
# X is low 0111..11 then Y above that, so (X^Y)&1 is
# Parity = lowbit(N) ^ bit_above_lowest_zero(N)
{
my $path = Math::PlanePath::DigitGroups->new;
my $bad = 0;
foreach my $n (0 .. 0xFFFF) {
my ($x, $y) = $path->n_to_xy ($n);
my $path_value = ($x + $y) % 2;
my $a_value = parity_bitwise($n);
if ($path_value != $a_value) {
MyTestHelpers::diag ("diff n=$n path=$path_value acalc=$a_value");
MyTestHelpers::diag (" xy=$x,$y");
last if ++$bad > 10;
}
}
ok ($bad, 0, "parity_bitwise()");
}
sub parity_bitwise {
my ($n) = @_;
return ($n & 1) ^ bit_above_lowest_zero($n);
}
sub bit_above_lowest_zero {
my ($n) = @_;
for (;;) {
if (($n % 2) == 0) {
last;
}
$n = int($n/2);
}
$n = int($n/2);
return ($n % 2);
}
#------------------------------------------------------------------------------
# A084472 - X axis in binary, excluding 0
MyOEIS::compare_values
(anum => 'A084472',
func => sub {
my ($count) = @_;
my @got;
my $path = Math::PlanePath::DigitGroups->new;
for (my $x = 1; @got < $count; $x++) {
my $n = $path->xy_to_n ($x,0);
push @got, to_binary($n);
}
return \@got;
});
sub to_binary {
my ($n) = @_;
return ($n < 0 ? '-' : '') . sprintf('%b', abs($n));
}
#------------------------------------------------------------------------------
# A060142 - X axis sorted
MyOEIS::compare_values
(anum => 'A060142',
func => sub {
my ($count) = @_;
my @got;
my $path = Math::PlanePath::DigitGroups->new;
for (my $x = 0; @got < 16 * $count; $x++) {
push @got, $path->xy_to_n ($x,0);
}
@got = sort {$a<=>$b} @got;
$#got = $count-1;
return \@got;
});
#------------------------------------------------------------------------------
exit 0;
|
