org.geotools.filter.function
Class Collection_AverageFunction
java.lang.Object
org.geotools.filter.expression.ExpressionAbstract
org.geotools.filter.DefaultExpression
org.geotools.filter.FunctionExpressionImpl
org.geotools.filter.function.Collection_AverageFunction
- All Implemented Interfaces:
- Factory, ExpressionType, FunctionExpression, org.opengis.filter.expression.Expression, org.opengis.filter.expression.Function
public class Collection_AverageFunction
- extends FunctionExpressionImpl
Calculates the average value of an attribute for a given FeatureCollection
and Expression.
- Since:
- 2.2M2
- Author:
- Cory Horner
Fields inherited from interface org.geotools.filter.ExpressionType |
ATTRIBUTE, ATTRIBUTE_DOUBLE, ATTRIBUTE_GEOMETRY, ATTRIBUTE_INTEGER, ATTRIBUTE_STRING, ATTRIBUTE_UNDECLARED, FUNCTION, LITERAL_DOUBLE, LITERAL_GEOMETRY, LITERAL_INTEGER, LITERAL_LONG, LITERAL_STRING, LITERAL_UNDECLARED, MATH_ADD, MATH_DIVIDE, MATH_MULTIPLY, MATH_SUBTRACT |
Fields inherited from interface org.opengis.filter.expression.Expression |
NIL |
Method Summary |
java.lang.Object |
evaluate(java.lang.Object feature)
This method checks if the object is an instance of Feature and
if so, calls through to #evaluate(Feature) . |
int |
getArgCount()
Gets the number of arguments that are set. |
void |
setExpression(Expression e)
|
void |
setParameters(java.util.List params)
The provided arguments are evaulated with respect to the
FeatureCollection. |
java.lang.String |
toString()
Return this function as a string. |
Methods inherited from class org.geotools.filter.FunctionExpressionImpl |
accept, equals, getArgs, getExpression, getFallbackValue, getImplementationHints, getName, getParameters, getType, setArgs, setFallbackValue, setName |
Methods inherited from class java.lang.Object |
clone, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait |
Methods inherited from interface org.opengis.filter.expression.Expression |
evaluate |
Collection_AverageFunction
public Collection_AverageFunction()
- Creates a new instance of Collection_AverageFunction
getArgCount
public int getArgCount()
- Description copied from class:
FunctionExpressionImpl
- Gets the number of arguments that are set.
- Specified by:
getArgCount
in interface FunctionExpression
- Specified by:
getArgCount
in class FunctionExpressionImpl
- Returns:
- the number of args.
setParameters
public void setParameters(java.util.List params)
- The provided arguments are evaulated with respect to the
FeatureCollection.
For an aggregate function (like average) please use the WFS mandated XPath
syntax to refer to featureMember content.
To refer to all 'X': featureMember/asterisk/X
- Specified by:
setParameters
in interface FunctionExpression
- Overrides:
setParameters
in class FunctionExpressionImpl
- Parameters:
args
- DOCUMENT ME!
- Throws:
java.lang.IllegalArgumentException
- DOCUMENT ME!
evaluate
public java.lang.Object evaluate(java.lang.Object feature)
- Description copied from class:
DefaultExpression
- This method checks if the object is an instance of
Feature
and
if so, calls through to #evaluate(Feature)
. This is done
to maintain backwards compatability with previous version of Expression api
which depended on Feature. If the object is not an instance of feature
the super implementation is called.
- Specified by:
evaluate
in interface org.opengis.filter.expression.Expression
- Overrides:
evaluate
in class DefaultExpression
setExpression
public void setExpression(Expression e)
toString
public java.lang.String toString()
- Return this function as a string.
- Overrides:
toString
in class FunctionExpressionImpl
- Returns:
- String representation of this average function.
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