Weibull distribution

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Format: VoseWeibull(a, b, U)

Weibull equations

Examples of the Weibull distribution are given below:

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Uses

The Weibull distribution is often used to model the time until occurrence of an event where the probability of occurrence changes with time (the process has 'memory'), as opposed to the Exponential distribution where the probability of occurrence remains constant ('memoryless'). It has also been used to model variation in wind speed at a specific site. Example: Light bulbs.

Comments

The Weibull distribution becomes an exponential distribution when a = 1, i.e. Weibull(1, b) = Expon(b). The Weibull distribution is very close to the Normal distribution when b= 3.25. The Weibull distribution is named after the Swedish physicist Dr E. H. Wallodi Weibull (1887-1979)  who used it to model the distribution of the breaking strengths of materials.

Alternative parametrizations

The WeibulAlt distribution determines a Weibull distribution defined by two percentiles.

VoseFunctions for this distribution

VoseWeibull generates values from this distribution or calculates a percentile

VoseWeibullObject constructs a distribution object for this distribution

VoseWeibullProb returns the probability density or cumulative distribution function for this distribution

VoseWeibullProb10 returns the log10 of the probability density or cumulative distribution function  

VoseWeibullFit generates values from this distribution fitted to data, or calculates a percentile from the fitted distribution

VoseWeibullFitObject constructs a distribution object of this distribution fitted to data

VoseWeibullFitP returns the parameters of this distribution fitted to data

See Also