Classifier
^^^^^^^^^^

A classifier captures a group of values (either expressed explicitly or as a range) providing a title to each group.


.. image:: /images/classifier.PNG

You can consider a Classifier as a set of groups into which you can sort your data:

* ExplicitClassifier
  
  Definition of explicit classifier by hand:
  
  .. literalinclude:: /../src/main/java/org/geotools/brewer/BrewerExamples.java
    :language: java
    :start-after: // explicitClassifierExample start
    :end-before: // explicitClassifierExample end
  
* RangedClassifier
  
  Definition of a ranged classifier by hand:
  
  .. literalinclude:: /../src/main/java/org/geotools/brewer/BrewerExamples.java
    :language: java
    :start-after: // rangedClassifierExample start
    :end-before: // rangedClassifierExample end
  
* As shown above each group can be provided with a title; these titles will be used in the generated styles:
  
  .. literalinclude:: /../src/main/java/org/geotools/brewer/BrewerExamples.java
     :language: java
     :start-after: // classiferExample2 start
     :end-before: // classiferExample2 end
  
* You can also automatically generate a Classifier from a FeatureCollection.
  
  The following "classifier" functions are available:
  
  * EqualInterval - classifier where each group represents the same sized range
  * Jenks - generate the Jenks' Natural Breaks classification
  * Quantile - classifier with an even number of items in each group
  * StandardDeviation - generated using the standard deviation method
  * UniqueInterval - variation of EqualInterval that takes into account unique values
  
  Here is the code example with quantile:
  
  .. literalinclude:: /../src/main/java/org/geotools/brewer/BrewerExamples.java
    :language: java
    :start-after: // classiferExample start
    :end-before: // classiferExample end
    
  Example using EqualInterval to break down a continuous range of values (such as height):
  
  .. literalinclude:: /../src/main/java/org/geotools/brewer/BrewerExamples.java
    :language: java
    :start-after: // classiferEqualInterval start
    :end-before: // classiferEqualInterval end
  
  Example using Quantile to break up a list of items (such as zones):
  
  .. literalinclude:: /../src/main/java/org/geotools/brewer/BrewerExamples.java
    :language: java
    :start-after: // classiferQuantile start
    :end-before: // classiferQuantile end