1Math::NumSeq::AllPrimeFUascetrorCso(n3t)ributed Perl DocMuamtehn:t:aNtuimoSneq::AllPrimeFactors(3)
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6 Math::NumSeq::AllPrimeFactors -- prime factors of the integers
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9 use Math::NumSeq::AllPrimeFactors;
10 my $seq = Math::NumSeq::AllPrimeFactors->new;
11 my ($i, $value) = $seq->next;
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14 This is a list of the prime factors of the integers 2, 3, 4, etc
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16 starting i=1
17 2, 3, 2, 2, 5, 2, 3, 7, 2, 2, 2, 3, 3, 2, 5, 11, ...
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19 \--/ \--/ \-----/ \--/ \--/
20 4 5 6 7 8 9 10 11
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22 Order
23 The optional "order" parameter (a string) can control the order of the
24 primes within each integer,
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26 "ascending" the default
27 "descending"
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29 For example "descending" rearranges the values to
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31 # order => "descending"
32 2, 3, 2, 2, 5, 3, 2, 7, 2, 2, 2, 3, 3, 5, 2, 11, ...
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34 \--/ \--/ \-----/ \--/ \--/
35 4 5 6 7 8 9 10 11
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37 The first difference is 3,2 for 6 (instead of 2,3).
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39 Multiplicity
40 Option "multiplicity => "distinct"" can give just one copy of each
41 prime factor.
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43 # multiplicity => "distinct"
44 2, 3, 2, 5, 2, 3, 7, 2, 3, 2, 5, 11, ...
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46 \--/ \--/
47 4 5 6 7 8 9 10 11
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49 On Values
50 Option "on_values" can give the prime factors of just some integers,
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52 "all" the default
53 "composites" the non-primes from 4 onwards
54 "odd" odd integers 3 onwards
55 "even" even integers 2 onwards
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57 "odd" is not simply a matter of filtering out 2s from the sequence,
58 since it takes the other primes from the even integers too, such as the
59 3 from 6.
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61 # on_values => "odd"
62 3, 5, 7, 3, 3, 11, 13, 3, 5, 17,
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64 \--/ \--/
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68 See "FUNCTIONS" in Math::NumSeq for behaviour common to all sequence
69 classes.
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71 "$seq = Math::NumSeq::AllPrimeFactors->new ()"
72 "$seq = Math::NumSeq::AllPrimeFactors->new (order => $str, multiplicity
73 => $str, on_values => $str)"
74 Create and return a new sequence object.
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76 "$bool = $seq->pred($value)"
77 Return true if $value occurs in the sequence. This simply means
78 $value a prime, or for "on_values=>'odd'" an odd prime.
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81 Math::NumSeq, Math::NumSeq::PrimeFactorCount, Math::NumSeq::AllDigits
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84 <http://user42.tuxfamily.org/math-numseq/index.html>
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87 Copyright 2012, 2013, 2014, 2016, 2019 Kevin Ryde
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89 Math-NumSeq is free software; you can redistribute it and/or modify it
90 under the terms of the GNU General Public License as published by the
91 Free Software Foundation; either version 3, or (at your option) any
92 later version.
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94 Math-NumSeq is distributed in the hope that it will be useful, but
95 WITHOUT ANY WARRANTY; without even the implied warranty of
96 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
97 General Public License for more details.
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99 You should have received a copy of the GNU General Public License along
100 with Math-NumSeq. If not, see <http://www.gnu.org/licenses/>.
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104perl v5.32.0 2020-07-28 Math::NumSeq::AllPrimeFactors(3)