WorksheetFunction.GammaInv(Double, Double, Double) Method

Reference

Definition

Namespace:: Microsoft.Office.Interop.Excel

Assembly:: Microsoft.Office.Interop.Excel.dll

Important

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Returns the inverse of the gamma cumulative distribution. If p = GAMMADIST(x,...), then GAMMAINV(p,...) = x.

public:
 double GammaInv(double Arg1, double Arg2, double Arg3);

public double GammaInv (double Arg1, double Arg2, double Arg3);

Public Function GammaInv (Arg1 As Double, Arg2 As Double, Arg3 As Double) As Double

Parameters

Arg1: Double

Probability - the probability associated with the gamma distribution.

Arg2: Double

Alpha - a parameter to the distribution.

Arg3: Double

Beta - a parameter to the distribution. If beta = 1, GammaInv returns the standard gamma distribution.

Returns

Double

Remarks

Important: This function has been replaced with one or more new functions that may provide improved accuracy and whose names better reflect their usage. This function is still available for compatibility with earlier versions of Excel. However, if backward compatibility is not required, you should consider using the new functions from now on, because they more accurately describe their functionality.For more information about the new function, see the Gamma_Inv(Double, Double, Double) method.

You can use this function to study a variable whose distribution may be skewed.

If any argument is text, GammaInv returns the #VALUE! error value.

If probability < 0 or probability > 1, GammaInv returns the #NUM! error value.

If alpha ≤ 0 or if beta ≤ 0, GammaInv returns the #NUM! error value.

Given a value for probability, GammaInv seeks that value x such that GAMMADIST(x, alpha, beta, TRUE) = probability. Thus, precision of GammaInv depends on precision of GammaDist(Double, Double, Double, Boolean). GammaInv uses an iterative search technique. If the search has not converged after 64 iterations, the function returns the #N/A error value.

Applies to