org.geotools.filter.visitor

Interface Categorize

All Superinterfaces:

Expression, Function

@XmlElement(value="Categorize")
public interface Categorize
extends Function

Categorization: The transformation of continuous values to distinct values. This is for example needed to generate choropleth maps from continuous attributes. Another example would be the stepwise selection of different text heights or line widths in dependence from such an attribute.

In case the Categorize (or Interpolate) function is used inside a RasterSymbolizer as a ColorMap, the LookupValue is set to the fixed value “Rasterdata”.

Author:

Johann Sorel (Geomatys)

Field Summary

Fields inherited from interface Expression

NIL

Method Summary

Modifier and Type	Method and Description
ThreshholdsBelongTo	getBelongTo() Get the function direction.
Expression	getLookupValue() Get lookup value.
SortedMap<Literal,Literal>	getThresholds() The Thresholds have to be specified in ascending order and (like the LookupValue) have to be of a uniform and orderable type.

Methods inherited from interface Function

getFallbackValue, getFunctionName, getName, getParameters

Methods inherited from interface Expression

accept, evaluate, evaluate

Method Detail

getLookupValue

@XmlElement(value="LookupValue")
Expression getLookupValue()

Get lookup value.

Returns:

Expression

getThresholds

SortedMap<Literal,Literal> getThresholds()

The Thresholds have to be specified in ascending order and (like the LookupValue) have to be of a uniform and orderable type. The value of the function is determined by looking up into which interval between two thresholds the LookupValue falls. The first interval ranges from -Infinity to the first given threshold and the last one accordingly from the last threshold to +Infinity.

getBelongTo

@XmlElement(value="ThreshholdsBelongTo")
ThreshholdsBelongTo getBelongTo()

Get the function direction. Default is SUCCEEDING.

Returns:

SUCCEEDING or PRECEDING