Top Description Fields Constructors Methods
org.apache.poi.ss.formula.functions

public final Class Delta

extends Fixed2ArgFunction
implements FreeRefFunction
Class Inheritance
All Implemented Interfaces
org.apache.poi.ss.formula.functions.FreeRefFunction
Imports
org.apache.poi.ss.formula.OperationEvaluationContext, org.apache.poi.ss.formula.eval.ErrorEval, .EvaluationException, .NumberEval, .OperandResolver, .ValueEval
Implementation for Excel DELTA() function.

Syntax:
DELTA (number1,number2 )

Tests whether two values are equal. Returns 1 if number1 = number2; returns 0 otherwise. Use this function to filter a set of values. For example, by summing several DELTA functions you calculate the count of equal pairs. This function is also known as the Kronecker Delta function.

Field Summary

Modifier and TypeField and Description
public static final FreeRefFunction
instance

private static final NumberEval
ONE

private static final NumberEval
ZERO

Constructor Summary

AccessConstructor and Description
public
Delta()

Method Summary

Modifier and TypeMethod and Description
public ValueEval
evaluate(int srcRowIndex, int srcColumnIndex, ValueEval arg1, ValueEval arg2)

Implements org.apache.poi.ss.formula.functions.Function2Arg.evaluate.

see Function#evaluate(ValueEval[], int, int)

public ValueEval
evaluate(ValueEval[]
the pre-evaluated arguments for this function. args is never null, nor are any of its elements.
args, OperationEvaluationContext
primarily used to identify the source cell containing the formula being evaluated. may also be used to dynamically create reference evals.
ec)

Implements org.apache.poi.ss.formula.functions.FreeRefFunction.evaluate.

private static Double
evaluateValue(ValueEval arg, int srcRowIndex, int srcColumnIndex)

Inherited from org.apache.poi.ss.formula.functions.Fixed2ArgFunction:
evaluate

Field Detail

instanceback to summary
public static final FreeRefFunction instance
ONEback to summary
private static final NumberEval ONE
ZEROback to summary
private static final NumberEval ZERO

Constructor Detail

Deltaback to summary
public Delta()

Method Detail

evaluateback to summary
public ValueEval evaluate(int srcRowIndex, int srcColumnIndex, ValueEval arg1, ValueEval arg2)

Implements org.apache.poi.ss.formula.functions.Function2Arg.evaluate.

Doc from org.apache.poi.ss.formula.functions.Function2Arg.evaluate.

see Function#evaluate(ValueEval[], int, int)

Annotations
@Override
evaluateback to summary
public ValueEval evaluate(ValueEval[] args, OperationEvaluationContext ec)

Implements org.apache.poi.ss.formula.functions.FreeRefFunction.evaluate.

Parameters
args:ValueEval[]

Doc from org.apache.poi.ss.formula.functions.FreeRefFunction.evaluate.

the pre-evaluated arguments for this function. args is never null, nor are any of its elements.

ec:OperationEvaluationContext

Doc from org.apache.poi.ss.formula.functions.FreeRefFunction.evaluate.

primarily used to identify the source cell containing the formula being evaluated. may also be used to dynamically create reference evals.

Returns:ValueEval

Doc from org.apache.poi.ss.formula.functions.FreeRefFunction.evaluate.

never null. Possibly an instance of ErrorEval in the case of a specified Excel error (Exceptions are never thrown to represent Excel errors).

Annotations
@Override
evaluateValueback to summary
private static Double evaluateValue(ValueEval arg, int srcRowIndex, int srcColumnIndex) throws EvaluationException