File Coverage

blib/lib/Math/Business/WMA.pm

Criterion	Covered	Total	%
statement	39	41	95.1
branch	9	12	75.0
condition			n/a
subroutine	7	9	77.7
pod	0	6	0.0
total	55	68	80.8

package Math::Business::WMA;

use strict;
use warnings;
use Carp;

1;

sub tag { (shift)->[-1] }

sub recommended { croak "no recommendation" }

sub new {
    my $class = shift;
    my $this  = bless [], $class;

    my $days = shift;
    if( defined $days ) {
        $this->set_days( $days );
    }

    return $this;
}

sub set_days {
    my $this = shift;
    my $arg  = int(shift);

    croak "days must be a positive non-zero even integer" if $arg <= 0;
    @$this = (
        $arg,
        ($arg*($arg+1))/2,
        [],     # the data (we actually need to store it, although we can avoid calculating much of it)
        undef,  # the sum of the data
        undef,  # the the last numerator
        undef,  # the WMA

        undef,  # tag must be last
    );

    $this->[-1] = "WMA($arg)";
}

sub insert {
    my $this = shift;
    my ($N, $D, $dat, $total_m, $numerator_m, $EMA) = @$this;

    croak "You must set the number of days before you try to insert" if not defined $N;

    my $old;
    while( defined( my $P = shift ) ) {
        push @$dat, $P;

        if( @$dat > $N ) {
            $old = shift @$dat;

            $numerator_m = $numerator_m + $P*$N - $total_m;
                $total_m =     $total_m + $P - $old;

        } elsif( @$dat == $N ) {
            $old = 1;
            my $x = 1;

            $total_m = $numerator_m = 0;

            $numerator_m += $_ for map {$_*$x++} @$dat;
                $total_m += $_ for @$dat;
        }
    }

    @$this = ($N, $D, $dat, $total_m, $numerator_m, (defined($old) ? $numerator_m/$D:undef));
}

sub query {
    my $this = shift;

    return $this->[5];
}

__END__