libmath-planepath-perl 117-1 / usr / share / perl5 / Math / PlanePath / Base / Generic.pm

This file is indexed.

/usr/share/perl5/Math/PlanePath/Base/Generic.pm is in libmath-planepath-perl 117-1.

This file is owned by root:root, with mode 0o644.

The actual contents of the file can be viewed below. 

  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
# Copyright 2010, 2011, 2012, 2013, 2014 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/>.


package Math::PlanePath::Base::Generic;
use 5.004;
use strict;

use vars '$VERSION','@ISA','@EXPORT_OK';
$VERSION = 117;

use Exporter;
@ISA = ('Exporter');
@EXPORT_OK = ('round_nearest',

              # not documented yet
              'is_infinite',
              'floor',
              'xy_is_even');

# uncomment this to run the ### lines
#use Smart::Comments;


# with a view to being friendly to BigRat/BigFloat
sub round_nearest {
  my ($x) = @_;
  ### round_nearest(): "$x", $x

  # BigRat through to perl 5.12.4 has some dodginess giving a bigint -0
  # which is considered !=0.  Adding +0 to numify seems to avoid the problem.
  my $int = int($x) + 0;
  if ($x == $int) {
    ### is an integer ...
    return $x;
  }
  $x -= $int;
  ### int:  "$int"
  ### frac: "$x"
  if ($x >= .5) {
    ### round up ...
    return $int + 1;
  }
  if ($x < -.5) {
    ### round down ...
    return $int - 1;
  }
  ### within +/- .5 ...
  return $int;
}

use constant parameter_info_nstart0 => { name        => 'n_start',
                                         share_key   => 'n_start_0',
                                         display     => 'N Start',
                                         type        => 'integer',
                                         default     => 0,
                                         width       => 3,
                                         description => 'Starting N.',
                                       };
use constant parameter_info_nstart1 => { name        => 'n_start',
                                         share_key   => 'n_start_1',
                                         display     => 'N Start',
                                         type        => 'integer',
                                         default     => 1,
                                         width       => 3,
                                         description => 'Starting N.',
                                       };

#------------------------------------------------------------------------------
# these not documented ...

sub is_infinite {
  my ($x) = @_;
  return ($x != $x         # nan
          || ($x != 0 && $x == 2*$x));  # inf
}

# With a view to being friendly to BigRat/BigFloat.
#
# For reference, POSIX::floor() in perl 5.12.4 is a bit bizarre on UV=64bit
# and NV=53bit double.  UV=2^64-1 rounds up to NV=2^64 which floor() then
# returns, so floor() in fact increases the value of what was an integer
# already.
#
# not documented yet
sub floor {
  my ($x) = @_;
  ### floor(): "$x", $x
  my $int = int($x);
  if ($x == $int) {
    ### is an integer ...
    return $x;
  }
  $x -= $int;
  ### frac: "$x"
  if ($x >= 0) {
    ### frac is non-negative ...
    return $int;
  } else {
    ### frac is negative ...
    return $int-1;
  }
}

# not documented yet
sub xy_is_visited_quad1 {
  my ($self, $x, $y) = @_;
  return ! (2*$x < -1 || 2*$y < -1);
}
# not documented yet
sub xy_is_visited_quad12 {
  my ($self, $x, $y) = @_;
  return (2*$y >= -1);
}
# not documented yet
sub _xy_is_visited_x_positive {
  my ($self, $x, $y) = @_;
  return (2*$x >= -1);
}
# not documented yet
sub xy_is_even {
  my ($self, $x, $y) = @_;
  return (round_nearest($x)%2 == round_nearest($y)%2);
}

1;
__END__

=for stopwords Ryde Math-PlanePath PlanePath hashref initializer

=head1 NAME

Math::PlanePath::Base::Generic -- various path helpers

=for test_synopsis my $x

=head1 SYNOPSIS

 use Math::PlanePath::Base::Generic 'round_nearest';
 $x = round_nearest($x);

=head1 DESCRIPTION

This is a few generic helper functions for the PlanePath code.  They're
designed to work on plain Perl integers and floats and in some cases there's
some special support for C<Math::BigInt>.

=head1 EXPORTS

Nothing is exported by default but each function below can be as in the
usual L<Exporter> style,

    use Math::PlanePath::Base::Generic 'round_nearest';

(But not C<parameter_info_nstart0()> and C<parameter_info_nstart1()>, for
the reason described below.)

=head1 FUNCTIONS

=head2 Generic

=over 4

=item C<$x = round_nearest ($x)>

Return C<$x> rounded to the nearest integer.  If C<$x> is half way, such as
2.5 then it's round upwards to 3.

   $x = round_nearest($x);

=item C<$href = Math::PlanePath::Base::Generic::parameter_info_nstart0()>

=item C<$href = Math::PlanePath::Base::Generic::parameter_info_nstart1()>

Return an C<n_start> parameter hashref suitable for use in a
C<parameter_info_array()>, with default either 0 or 1.  For example,

    # alone
    package Math::PlanePath::MySubclass;
    use constant parameter_info_array =>
      [ Math::PlanePath::Base::Generic::parameter_info_nstart1() ];

    # or with other parameters too
    package Math::PlanePath::MySubclass;
    use constant parameter_info_array =>
      [
       { name            => 'something',
         type            => 'integer',
         default         => '123',
       },
       Math::PlanePath::Base::Generic::parameter_info_nstart1(),
      ];

This function is not exportable since it's meant for a one-off call in an
initializer and so no need to import it for repeated use.

=back

=head1 SEE ALSO

L<Math::PlanePath>,
L<Math::PlanePath::Base::Digits>,
L<Math::PlanePath::Base::NSEW>

=head1 HOME PAGE

L<http://user42.tuxfamily.org/math-planepath/index.html>

=head1 LICENSE

Copyright 2010, 2011, 2012, 2013, 2014 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/>.

=cut

APT Browse - Built by Thomas Orozco.