File Coverage

blib/lib/Math/EMA.pm

Criterion	Covered	Total	%
statement	27	28	96.4
branch	2	2	100.0
condition	1	3	33.3
subroutine	9	9	100.0
pod	2	3	66.6
total	41	45	91.1

package Math::EMA;

use 5.008003;
use strict;
use warnings;

our $VERSION = '0.03';

our @attributes;
BEGIN {
  # define attributes and implement accessor methods
  @attributes=qw/alpha ema/;
  for( my $i=0; $i<@attributes; $i++ ) {
    my $method_num=$i;
    ## no critic
    no strict 'refs';
    *{__PACKAGE__.'::'.$attributes[$method_num]}=
      sub : lvalue {$_[0]->[$method_num]};
    ## use critic
  }
}

sub new {
  my $class=ref($_[0]) || $_[0];

  my $I=bless []=>$class;
  $I->alpha=exp(log(0.001)/10);

  for( my $i=1; $i<@_; $i+=2 ) {
    $I->{$_[$i]}=$_[$i+1];
  }

  return $I;
}

sub set_param {
  my ($I, $count, $weight)=@_;

  $I->alpha=exp(log($weight)/$count);
}

sub add {
  my ($I, $value)=@_;

  $I->ema=defined($I->ema) ? (1-$I->alpha)*$value + $I->alpha*$I->ema : $value;
}

1;
__END__