ParetoDistribution

ParetoDistribution[k,α]
表示极小值参数为 k、形状参数为 α 的帕累托(Pareto )分布.

ParetoDistribution[k,α,μ]
表示帕累托II分布,位置参数为 μ.

ParetoDistribution[k,α,γ,μ]
表示帕累托IV分布,形状参数为 γ.

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  • 时,一个帕累托(Pareto )分布的 的概率密度与 成正比;当 时,概率密度为 0. »
  • ParetoDistribution 包括类型 I、II、III 和 IV 的分布:
  • ParetoDistribution[k,α]帕累托I分布
    ParetoDistribution[k,α,μ]帕累托II分布
    ParetoDistribution[k,1,γ,μ]帕累托III分布
    ParetoDistribution[k,α,γ,μ]帕累托IV分布
  • ParetoDistribution[k,α,0] 也称为 Lomax 分布.
  • 在帕累托分布中 的生存函数对应于:
  • ParetoDistribution[k,α]
    ParetoDistribution[k,α,μ]
    ParetoDistribution[k,α,γ,μ]
  • ParetoDistribution 允许 kαγ 可以是任意正实数,μ 可以是任意实数.
  • ParetoDistribution 可以与 MeanCDFRandomVariate 等函数一起使用.  »

背景
背景

  • ParetoDistribution represents a statistical distribution belonging to one of four typestype I, II, III, or IVas determined by its argument structure. The overall shape of the probability distribution function (PDF) of a Pareto distribution varies significantly based on its arguments. For example, the PDF of types I and II Pareto distributions are monotonically decreasing while type IV distributions may have a single peak. In addition, the PDF of all types of ParetoDistribution are defined over a half-infinite interval and the tails of the PDF are "fat" in the sense that the PDF decreases as a power law rather than decreasing exponentially for large values . (This behavior can be made quantitatively precise by analyzing the SurvivalFunction of the distribution.)
  • Pareto distributions originate with Italian economist Vilfredo Pareto, who noticed that approximately 80% of the peas in his garden were produced by roughly 20% of the pea pods. Later, Pareto observed that wealth distribution among nations followed a similar distribution, a result that led him to devise the so-called 80-20 rule (also called the Pareto principle), the basis for which is a type-I distribution corresponding to ParetoDistribution[k,α] with . Pareto distributions also arise in a number of other mathematical and scientific contexts and are applicable to phenomena including hard disk error rates, price returns among stocks, and BoseEinstein statistics.
  • RandomVariate can be used to give one or more machine- or arbitrary-precision (the latter via the WorkingPrecision option) pseudorandom variates from a Pareto distribution. Distributed[x,ParetoDistribution[k,α]], written more concisely as , can be used to assert that a random variable x is distributed according to a type-I Pareto distribution. Here, the positive parameter α is known as the Pareto index. Such an assertion can then be used in functions such as Probability, NProbability, Expectation, and NExpectation.
  • The probability distribution and cumulative density functions for type-I Pareto distributions may be given using PDF[ParetoDistribution[k,α]],x] and CDF[ParetoDistribution[k,α]],x], with similar expressions for type II, III, and IV distributions. In general, Pareto distributions have PDFs that are proportional to . The mean, median, variance, raw moments, and central moments may be computed using Mean, Median, Variance, Moment, and CentralMoment, respectively.
  • DistributionFitTest can be used to test if a given dataset is consistent with a Pareto distribution, EstimatedDistribution to estimate a Pareto parametric distribution from given data, and FindDistributionParameters to fit data to a Pareto distribution. ProbabilityPlot can be used to generate a plot of the CDF of given data against the CDF of a symbolic Pareto distribution and QuantilePlot to generate a plot of the quantiles of given data against the quantiles of a symbolic Pareto distribution.
  • TransformedDistribution can be used to represent a transformed Pareto distribution, CensoredDistribution to represent the distribution of values censored between upper and lower values, and TruncatedDistribution to represent the distribution of values truncated between upper and lower values. CopulaDistribution can be used to build higher-dimensional distributions that contain a Pareto distribution and ProductDistribution can be used to compute a joint distribution with independent component distributions involving Pareto distributions.
  • ParetoDistribution is closely related to a number of other distributions. For example, the Pareto distribution is the continuous analogue of ZipfDistribution. As is result of its definition, the reciprocal of a Paretodistributed random variable follows the PowerDistribution. Furthermore, the distribution of the appropriately centered and scaled total values of independent samples of a Pareto-distributed random variable approaches a StableDistribution, while an exponential function of a random variable that follows ExponentialDistribution follows a ParetoDistribution. ParetoDistribution is also closely related to LogNormalDistribution, BenktanderWeibullDistribution, BeniniDistribution, BenktanderGibratDistribution, ChiSquareDistribution, PearsonDistribution, and BetaPrimeDistribution.

范例范例打开所有单元关闭所有单元

基本范例  (12)基本范例  (12)

帕累托I分布的概率密度函数:

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帕累托I分布的累积分布函数:

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帕累托I分布的均值和方差:

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帕累托I分布的中位数:

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帕累托II分布的概率密度函数:

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帕累托II分布的累积分布函数:

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帕累托II分布的均值和方差:

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帕累托II分布的中位数:

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帕累托IV分布的概率密度函数:

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帕累托IV分布的累积分布函数:

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帕累托IV分布的均值和方差:

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帕累托IV分布的中位数:

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2007年引入
(6.0)
| 2010年更新
(8.0)