File Coverage

lib/Spreadsheet/Engine/Function/DDB.pm

Criterion	Covered	Total	%
statement	25	25	100.0
branch	2	2	100.0
condition	2	2	100.0
subroutine	7	7	100.0
pod	3	3	100.0
total	39	39	100.0

package Spreadsheet::Engine::Function::DDB;

use strict;
use warnings;

use base 'Spreadsheet::Engine::Fn::depreciation';
use List::Util 'min';

sub argument_count { -4 => 5 }
sub signature { 'n', 'n', '>=1', 'n', 'n' }

sub calculate {
  my ($self, $cost, $salvage, $lifetime, $period, $method) = @_;
  $method ||= 2;

  my $depreciation = 0;    # calculated for each period
  my $accumulated  = 0;    # accumulated by adding each period's

  # calculate for each period based on net from previous
  for my $i (1 .. min($period, $lifetime)) {
    $depreciation = ($cost - $accumulated) * ($method / $lifetime);
    {                      # don't go lower than salvage value
      my $bottom = $cost - $salvage - $accumulated;
      $depreciation = $bottom if $bottom < $depreciation;
    }
    $accumulated += $depreciation;
  }
  return $depreciation;
}

1;

__END__