FactDouble (Keikai Spreadsheet Build 6.0.0 API)

java.lang.Object
- org.apache.poi.ss.formula.functions.Fixed1ArgFunction
- - org.apache.poi.ss.formula.functions.FactDouble

All Implemented Interfaces:

FreeRefFunction, Function, Function1Arg
```
public class FactDouble
extends Fixed1ArgFunction
implements FreeRefFunction
```
Implementation for Excel FACTDOUBLE() function.
Syntax:
FACTDOUBLE (number)

Returns the double factorial of a number.
Number is the value for which to return the double factorial. If number is not an integer, it is truncated.
Remarks
- If number is nonnumeric, FACTDOUBLE returns the #VALUE! error value.
- If number is negative, FACTDOUBLE returns the #NUM! error value.
Use a cache for more speed of previously calculated factorial

Field Summary

Fields
Modifier and Type Field Description

static FreeRefFunction instance

Constructor Summary

Constructors
Constructor Description

FactDouble()

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`ValueEval`	`evaluate(int srcRowIndex, int srcColumnIndex, ValueEval numberVE)`	see `Function.evaluate(ValueEval[], int, int)`
`ValueEval`	`evaluate(ValueEval[] args, OperationEvaluationContext ec)`
`static BigInteger`	`factorial(int n)`

Methods inherited from class org.apache.poi.ss.formula.functions.Fixed1ArgFunction
evaluate, evaluate

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - instance
```
public static final FreeRefFunction instance
```
- Constructor Detail
  - FactDouble
```
public FactDouble()
```
- Method Detail
  - evaluate
```
public ValueEval evaluate(int srcRowIndex,
                          int srcColumnIndex,
                          ValueEval numberVE)
```
    Description copied from interface: Function1Arg
    
    see Function.evaluate(ValueEval[], int, int)
    
    Specified by:
    
    evaluate in interface Function1Arg
  - factorial
```
public static BigInteger factorial(int n)
```
  - evaluate
```
public ValueEval evaluate(ValueEval[] args,
                          OperationEvaluationContext ec)
```
    Specified by:
    
    evaluate in interface FreeRefFunction
    
    Parameters:
    
    args - the pre-evaluated arguments for this function. args is never null, nor are any of its elements.
    
    ec - primarily used to identify the source cell containing the formula being evaluated. may also be used to dynamically create reference evals.
    
    Returns:
    
    never null. Possibly an instance of ErrorEval in the case of a specified Excel error (Exceptions are never thrown to represent Excel errors).