org.geotools.filter
Class CategorizeFunction

Object
  extended by CategorizeFunction
All Implemented Interfaces:
Expression, Function

public class CategorizeFunction
extends Object
implements Function

Implementation of "Categorize" as a normal function.

This implementation is compatible with the Function interface; the parameter list can be used to set the threshold values etc...

This function expects:

  1. PropertyName; use "Rasterdata" to indicate this is a colour map
  2. Literal: lookup value
  3. Literal: threshold 1
  4. Literal: value 1
  5. Literal: threshold 2
  6. Literal: value 2
  7. Literal: (Optional) succeeding or preceding
In reality any expression will do.

Author:
Jody Garnett, Johann Sorel (Geomatys)

Nested Class Summary
static class CategorizeFunction.Name
          Describe how this function works.
 
Field Summary
static FunctionName NAME
          Make the instance of FunctionName available in a consistent spot.
static String PRECEDING
          Use as a literal value to indicate behaviour of threshold boundary
static String RASTER_DATA
          Use as a PropertyName when defining a color map.
static String SUCCEEDING
          Use as a literal value to indicate behaviour of threshold boundary
 
Fields inherited from interface Expression
NIL
 
Constructor Summary
CategorizeFunction()
           
CategorizeFunction(List<Expression> parameters, Literal fallback)
           
 
Method Summary
 Object accept(ExpressionVisitor visitor, Object extraData)
           
 Object evaluate(Object object)
           
<T> T
evaluate(Object object, Class<T> context)
           
 Literal getFallbackValue()
           
 String getName()
           
 List<Expression> getParameters()
           
 
Methods inherited from class Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

SUCCEEDING

public static final String SUCCEEDING
Use as a literal value to indicate behaviour of threshold boundary

See Also:
Constant Field Values

PRECEDING

public static final String PRECEDING
Use as a literal value to indicate behaviour of threshold boundary

See Also:
Constant Field Values

RASTER_DATA

public static final String RASTER_DATA
Use as a PropertyName when defining a color map. The "Raterdata" is expected to apply to only a single band; if multiple bands are provided it is probably a mistake; but we will use the maximum value (since we are working against a threshold).

See Also:
Constant Field Values

NAME

public static final FunctionName NAME
Make the instance of FunctionName available in a consistent spot.

Constructor Detail

CategorizeFunction

public CategorizeFunction()

CategorizeFunction

public CategorizeFunction(List<Expression> parameters,
                          Literal fallback)
Method Detail

getName

public String getName()
Specified by:
getName in interface Function

getParameters

public List<Expression> getParameters()
Specified by:
getParameters in interface Function

accept

public Object accept(ExpressionVisitor visitor,
                     Object extraData)
Specified by:
accept in interface Expression

evaluate

public Object evaluate(Object object)
Specified by:
evaluate in interface Expression

evaluate

public <T> T evaluate(Object object,
                      Class<T> context)
Specified by:
evaluate in interface Expression

getFallbackValue

public Literal getFallbackValue()
Specified by:
getFallbackValue in interface Function


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