Probabilities.WeibullPDF Method

Overload List

#SignatureDescription
1procedure WeibullPDF(const X: TDenseMtxVec; A: Double; B: Double; const Res: TDenseMtxVec);Weibull distribution PDF (vectorized).
2function WeibullPDF(x: Double; a: Double; b: Double): Double;Weibull probability density function (PDF).

Overload 1: procedure WeibullPDF(const X: TDenseMtxVec; A: Double; B: Double; const Res: TDenseMtxVec);

Weibull distribution PDF (vectorized).

#NameDescription
1XDefines distribution domain, real vector or matrix with positive real values.
2ADistribution scale parameter, real positive value.
3BDistribution shape parameter, real positive value.
4ResAfter calculation stores the PDF calculated from X, a and b. Length and Complex properties of Res are adjusted automatically to match Length and Complex properties of X.

Result: stored in self (calling object)

Overload 2: function WeibullPDF(x: Double; a: Double; b: Double): Double;

Weibull probability density function (PDF).

#NameDescription
1xFunction domain, zero or real positive value.
2aDistribution scale parameter, real positive value (rate-like: enters as exp(-a x^b)).
3bDistribution shape parameter, real positive value.

Returns: Double - the Weibull probability density function for value x using the parameters a and b. Parameters a and b must be positive, otherwise the result is NAN.

Remarks:

The Weibull probability density function, in the parameterization used here, is

PDF(x| a,b)=a b x^(b-1)exp(-a x^b), x >= 0

where a is the (rate-like) scale parameter and b the shape parameter. This maps to the standard scale s by s = a^{-1/b}. Domain: x >= 0, a > 0, b > 0. For a <= 0 or b <= 0 the result is NAN. At x = 0 the value is +INF when b < 1 and equals a when b = 1.

See Also: Probabilities.WeibullCDF, Probabilities.WeibullCDFInv