NAME

       Lire::Average - Lire class that implements the avg operator

SYNOPSIS

        use Lire::Average

DESCRIPTION

       Class that implements the avg operator. This operator will compute the average value of a
       DLF field in a group of DLF records.

       If the field used by average isn't a numeric fields, the number of different values in
       that field will be used as the numerator.

       It's possible to compute a weighted average by specifying a weighting field.

       By default, the average is a by record average. It's possible to compute a by different
       values average. The list of fields that's used to determine the different values if
       speficied in the by-fields attribute.

METHODS

   new( %params )
       Creates a new Lire::Average object. In addition to the values supported by its parents,
       the by-fields and weight attributes will be initialized to the values specified in the
       %params argument.

   by_fields( [$new_by_fields] )
       Returns the fields that are going to be used to count the different values which will made
       up the by part of the average.

       This a reference to an array of DLF field names.

       If the $new_by_fields parameter is set, it will be used as the new $by_fields value. It
       must be an array reference and should only contains valid field names for the current
       report specification's schema.

   weigth( [$new_weight] )
       Returns the DLF field's name by which the values will be multiplied before being summed.

       You can change the weight field by specifying a new name as the $new_weight parameter. Use
       undef to remove the use of a weighting field.

SEE ALSO

        Lire::ReportSpec(3pm), Lire::ReportOperator(3pm),
        Lire::Aggregator(3pm), Lire::Aggregate(3pm).

AUTHORS

        Francis J. Lacoste <flacoste@logreport.org>
        Wolfgang Sourdeau <wsourdea@logreport.org>

VERSION

       $Id: Average.pm,v 1.17 2008/03/09 19:27:30 vanbaal Exp $

COPYRIGHT

       Copyright (C) 2001-2004 Stichting LogReport Foundation LogReport@LogReport.org

       This file is part of Lire.

       Lire is free software; you can redistribute it and/or modify it under the terms of the GNU
       General Public License as published by the Free Software Foundation; either version 2 of
       the License, or (at your option) any later version.

       This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
       without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
       See the GNU General Public License for more details.

       You should have received a copy of the GNU General Public License along with this program
       (see COPYING); if not, check with http://www.gnu.org/copyleft/gpl.html.