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Statistics::Basic::StdDev.3pm

NAME

Statistics::Basic::StdDev - find the standard deviation of an array

SYNOPSIS

Invoke it this way:

     my $stddev = stddev(1,2,3);
 
 

Or this way:

     my $v1  = vector(1,2,3);
     my $std = stddev($v1);
 
 

And then either query the values or print them like so:

     print "The stddev of $v1: $std\n";
     my $sq = $std->query;
     my $s0 = 0+$std;
 
 

Create a 20 point ``moving'' stddev like so:

     my $sth = $dbh->prepare("select col1 from data where something");
     my $len = 20;
     my $std = stddev();
        $std->set_size($len);
 
     $sth->execute or die $dbh->errstr;
     $sth->bind_columns( my $val ) or die $dbh->errstr;
 
     my $count = $len;
     while( $sth->fetch ) {
 
         $std->insert( $val );
         if( -- $count <= 0 ) {
             print "StdDev: $std\n";
         }
     }
 
 

The full details are probably in the base module. If you have questions, just let me know.

AUTHOR

Paul Miller "<jettero@cpan.org>"

I am using this software in my own projects... If you find bugs, please please please let me know. :) Actually, let me know if you find it handy at all. Half the fun of releasing this stuff is knowing that people use it.

COPYRIGHT

Copyright 2009 Paul Miller --- Licensed under the LGPL

SEE ALSO

perl(1), Statistics::Basic