1Math::NumSeq::SqrtContiUnsueerdPCeornitordi(b3u)ted PerlMaDtohc:u:mNeunmtSaetqi:o:nSqrtContinuedPeriod(3)
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6 Math::NumSeq::SqrtContinuedPeriod -- period of the continued fraction
7 for sqrt(i)
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10 use Math::NumSeq::SqrtContinuedPeriod;
11 my $seq = Math::NumSeq::SqrtContinuedPeriod->new;
12 my ($i, $value) = $seq->next;
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15 This the period of the repeating part of the continued fraction
16 expansion of sqrt(i).
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18 0, 1, 2, 0, 1, 2, 4, 2, etc
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20 For example sqrt(12) is 3 then terms 2,6 repeating, which is period 2.
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22 1
23 sqrt(12) = 3 + -----------
24 2 + 1
25 -----------
26 6 + 1
27 ----------
28 2 + 1
29 ---------
30 6 + ... 2,6 repeating
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32 All square root continued fractions like this comprise an integer part
33 followed by repeating terms of some length. Perfect squares are an
34 integer part only, nothing further, and the period for them is taken to
35 be 0.
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37 The continued fraction calculation has denominator value at each stage
38 of the form
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40 den =(P+sqrt(S)) / Q
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42 with
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44 0 <= P <= root
45 0 < Q <= 2*root+1
46 where root=floor(sqrt(S))
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48 The limited range of P,Q means a finite set of combinations at most
49 root*(2*root+1), which is roughly 2*S. In practice it's much less.
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52 See "FUNCTIONS" in Math::NumSeq for behaviour common to all sequence
53 classes.
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55 "$seq = Math::NumSeq::SqrtContinuedPeriod->new (sqrt => $s)"
56 Create and return a new sequence object giving the Continued
57 expansion terms of "sqrt($s)".
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59 "$value = $seq->ith ($i)"
60 Return the period of sqrt($i).
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63 Math::NumSeq, Math::NumSeq::SqrtContinued
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66 <http://user42.tuxfamily.org/math-numseq/index.html>
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69 Copyright 2011, 2012, 2013, 2014, 2016, 2019 Kevin Ryde
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71 Math-NumSeq is free software; you can redistribute it and/or modify it
72 under the terms of the GNU General Public License as published by the
73 Free Software Foundation; either version 3, or (at your option) any
74 later version.
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76 Math-NumSeq is distributed in the hope that it will be useful, but
77 WITHOUT ANY WARRANTY; without even the implied warranty of
78 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
79 General Public License for more details.
80
81 You should have received a copy of the GNU General Public License along
82 with Math-NumSeq. If not, see <http://www.gnu.org/licenses/>.
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86perl v5.32.0 2020-07-2M8ath::NumSeq::SqrtContinuedPeriod(3)