WorksheetFunction.Gamma_Inv method (Excel)

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

Syntax

expression. Gamma_Inv( _Arg1_ , _Arg2_ , _Arg3_ )

expression A variable that represents a 'WorksheetFunction' object.

Parameters

Name Required/Optional Data type Description
Arg1 Required Double Probability - the probability associated with the gamma distribution.
Arg2 Required Double Alpha - a parameter to the distribution.
Arg3 Required Double Beta - a parameter to the distribution. If beta = 1, GAMMA_INV returns the standard gamma distribution.

Return value

Double

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. GAMMA_INV uses an iterative search technique. If the search has not converged after 100 iterations, the function returns the #N/A error value.

See also

WorksheetFunction Object

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