1Statistics::Basic::StdDUesve(r3)Contributed Perl DocumenSttaattiiosntics::Basic::StdDev(3)
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NAME

6       Statistics::Basic::StdDev - find the standard deviation of a list
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SYNOPSIS

9       Invoke it this way:
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11           my $stddev = stddev(1,2,3);
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13       Or this way:
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15           my $v1  = vector(1,2,3);
16           my $std = stddev($v1);
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18       And then either query the values or print them like so:
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20           print "The stddev of $v1: $std\n";
21           my $sq = $std->query;
22           my $s0 = 0+$std;
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24       Create a 20 point "moving" stddev like so:
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26           use Statistics::Basic qw(:all nofill);
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28           my $sth = $dbh->prepare("select col1 from data where something");
29           my $len = 20;
30           my $std = stddev()->set_size($len);
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32           $sth->execute or die $dbh->errstr;
33           $sth->bind_columns( my $val ) or die $dbh->errstr;
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35           while( $sth->fetch ) {
36               $std->insert( $val );
37               if( defined( my $s = $std->query ) ) {
38                   print "StdDev: $s\n";
39               }
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41               # This would also work:
42               # print "StdDev: $s\n" $std->query_filled;
43           }
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METHODS

46       new()
47           The constructor takes a list of values, a single array ref, or a
48           single Statistics::Basic::Vector as arguments.  It returns a
49           Statistics::Basic::StdDev object.
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51           Note: normally you'd use the mean() constructor, rather than
52           building these by hand using "new()".
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54       query_mean()
55           Returns the Statistics::Basic::Mean object used in the standard
56           deviation computation.
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58       _OVB::import()
59           This module also inherits all the overloads and methods from
60           Statistics::Basic::_OneVectorBase.
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OVERLOADS

63       This object is overloaded.  It tries to return an appropriate string
64       for the calculation or the value of the computation in numeric context.
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66       In boolean context, this object is always true (even when empty).
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AUTHOR

69       Paul Miller "<jettero@cpan.org>"
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71       I am using this software in my own projects...  If you find bugs,
72       please please please let me know. :) Actually, let me know if you find
73       it handy at all.  Half the fun of releasing this stuff is knowing that
74       people use it.
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77       Copyright 2009 Paul Miller -- Licensed under the LGPL
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SEE ALSO

80       perl(1), Statistics::Basic, Statistics::Basic::_OneVectorBase,
81       Statistics::Basic::Vector
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85perl v5.12.3                      2009-06-28      Statistics::Basic::StdDev(3)
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