WorksheetFunction.Gamma_Inv(Double, Double, Double) Method
Definition
Important
Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.
Returns the inverse of the gamma cumulative distribution. If p = GAMMA_DIST(x,...), then GAMMA_INV(p,...) = x.
public:
double Gamma_Inv(double Arg1, double Arg2, double Arg3);
public double Gamma_Inv (double Arg1, double Arg2, double Arg3);
Public Function Gamma_Inv (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, Gamma_Inv returns the standard gamma distribution.
Returns
Remarks
You can use this function to study a variable whose distribution may be skewed.
If any argument is text, Gamma_Inv returns the #VALUE! error value.
If probability < 0 or probability > 1, Gamma_Inv returns the #NUM! error value.
If alpha ≤ 0 or if beta ≤ 0, Gamma_Inv returns the #NUM! error value.
Given a value for probability, Gamma_Inv seeks that value x such that GAMMA_DIST(x, alpha, beta, TRUE) = probability. Thus, precision of Gamma_Inv depends on precision of Gamma_Dist(Double, Double, Double, Boolean). Gamma_Inv uses an iterative search technique. If the search has not converged after 100 iterations, the function returns the #N/A error value.