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WorksheetFunction.Weibull(Double, Double, Double, Boolean) Method

Definition

Returns the Weibull distribution. Use this distribution in reliability analysis, such as calculating a device's mean time to failure.

public:
 double Weibull(double Arg1, double Arg2, double Arg3, bool Arg4);
public double Weibull (double Arg1, double Arg2, double Arg3, bool Arg4);
Public Function Weibull (Arg1 As Double, Arg2 As Double, Arg3 As Double, Arg4 As Boolean) As Double

Parameters

Arg1
Double

X - the value at which to evaluate the function.

Arg2
Double

Alpha - a parameter to the distribution.

Arg3
Double

Beta - a parameter to the distribution.

Arg4
Boolean

Cumulative - determines the form of the function.

Returns

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 Weibull_Dist(Double, Double, Double, Boolean) method.

If x, alpha, or beta is nonnumeric, Weibull returns the #VALUE! error value. If x < 0, Weibull returns the #NUM! error value.

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

The equation for the Weibull cumulative distribution function is:

Figure 1: Equation for the Weibull cumulative distribution

The equation for the Weibull probability density function is:

Figure 2: Equation for the Weibull probability density

When alpha = 1, Weibull returns the exponential distribution with:

Figure 3: Equation

Applies to