 Statistics::Basic::Variance(3) find the variance of a list

## SYNOPSIS

Invoke it this way:

my \$variance = variance(1,2,3);

Or this way:

```    my \$v1  = vector(1,2,3);
my \$var = var(\$v1);
```

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

```    print "The variance of \$v1: \$variance\n";
my \$vq = \$var->query;
my \$v0 = 0+\$var;
```

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

```    use Statistics::Basic qw(:all nofill);
my \$sth = \$dbh->prepare("select col1 from data where something");
my \$len = 20;
my \$var = var()->set_size(\$len);
\$sth->execute or die \$dbh->errstr;
\$sth->bind_columns( my \$val ) or die \$dbh->errstr;
while( \$sth->fetch ) {
\$var->insert( \$val );
if( defined( my \$v = \$var->query ) ) {
print "Variance: \$v\n";
}
# This would also work:
# print "Variance: \$v\n" if \$var->query_filled;
}
```

## METHODS

new()
The constructor takes a list of values, a single array ref, or a single Statistics::Basic::Vector as arguments. It returns a Statistics::Basic::Variance object.

Note: normally you'd use the mean() constructor, rather than building these by hand using "new()".

query_mean()
Returns the Statistics::Basic::Mean object used in the variance computation.
_OVB::import()
This module also inherits all the overloads and methods from Statistics::Basic::_OneVectorBase.

## AUTHOR

Paul Miller "<[email protected]>"

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.