Rangegroup(3pm)

NAME
Lire::Group - Base class for implementation of the rangegroup aggregator

SYNOPSIS
    use Lire::Rangegroup;

DESCRIPTION
This module is the base class for implementation of the rangegroup aggregator. This aggregator will split the DLF records based on a numerical field. The so-called range groups creates numerical classes (e.g. 1-10, 11-20, etc.) and the DLF record will be grouped with other records which are in the same class.

CONSTRUCTOR

  new( %params )
Creates a new instance of a group aggregator. In addition to the normal report operator parameters, the rangegroup aggregator can take several parameters:

field
    This parameter is mandatory. It should be the name of the DLF field which will be used as key for this aggregator.

range-size
    This parameter is mandatory. This will be used as the size of each range group.

range-start
    The number at which the first range group starts. Defauls to 0.

min-value
    Value lower than this number will be sorted in the first range group.

max-value
    Value higher than this number will be sorted in the last range group.

size-scale
    This parameter can be used to create a logarithmic scale. In this case, each new range group will be size-scale bigger than the one that comes before it. For example, setting range-size=5 and size-scale=2 will create ranges like [0-5>, [5-15>, [15-35>, ...

METHODS

  field( [$new_field] )
Returns the name of the DLF field which is used as grouping key.

If the $new_field parameter is set, it changes the grouping field. This must be the name of a quantity type field in the report specifications DLF schema.

  range_start( [$new_start] )
Returns the number which is the starting bound of the first range group.

If the $new_start parameter is set, it changes the starting bound of the first range group. This should either be a positive integer or the name of one of the report specification's parameter.

  range_size( [$new_size] )
Returns the width of each range group.

If the $new_size parameter is set, it changes the width of each range group. This should either be a positive integer or the name of one of the report specification's parameter.

  min_value( [$new_min] )
Returns the number below which no new range groups will be created.

If the $new_min is set, it changes the lower bound below which no new groups will be created. This should either be a number or the name of one of the report specification's parameter.

  max_value( [$new_max] )
Returns the number above which no new range groups will be created.

If the $new_max is set, it changes the upper bound above which no new groups will be created. This should either be a number or the name of one of the report specification's parameter.

  size_scale( [$new_size_scale] )
Returns the multiplier that will be apply to each of the range group's width after the first one.

When this attribute is greater than 1, it creates a logarithmic scale where each new ranges is $size_scale wider than the precedent one.

If the $new_size_scale parameter is used, it changes the attribute to this new value. It should be a positive interger or can also be a parameter reference.

SEE ALSO
 Lire::ReportSpec(3pm), Lire::Group(3pm), Lire::ReportOperator(3pm),
 Lire::Aggregator(3pm)

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

VERSION
$Id: Rangegroup.pm,v 1.22 2004/07/02 16:09:24 flacoste 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 or write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.