File Coverage

blib/lib/Math/CMA.pm

Criterion	Covered	Total	%
statement	36	36	100.0
branch	5	6	83.3
condition			n/a
subroutine	5	5	100.0
pod	0	1	0.0
total	46	48	95.8

package Math::CMA;

use 5.010000;
use strict;
use warnings;
use List::Util qw/min max sum/;

require Exporter;

our @ISA = qw(Exporter);

our %EXPORT_TAGS = ( 'all' => [ qw(
  central_moving_averages
) ] );

our @EXPORT_OK = ( @{ $EXPORT_TAGS{'all'} } );

our @EXPORT = qw(

);

our $VERSION = '0.1';

sub central_moving_averages {
  my $smoothing = shift;
  my @series = @{shift()};
  my $count = min($smoothing, $#series);
  my $left = -$count;
  my $right = $count;
  my $sum = 0;
  my @result;

  return @series unless $count > 0;

  # sum first element and window to the right
  for (0 .. $count) {
    $sum += $series[$_];
  }

  # head
  while ($left < 0) {
    push @result, $sum / ($right + 1);
    $left++;
    $sum += $series[++$right] if $right < $#series;
  }

  # middle part
  while (1) {
    push @result, $sum / ($right - $left + 1);
    $sum -= $series[$left++];
    last if $right >= $#series;
    $sum += $series[++$right];
  }

  # tail
  while (@result < @series) {
    push @result, $sum / ($right - $left + 1);
    $sum -= $series[$left++];
  }

  @result;
}

1;
__END__