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weibulldistribution

Weibull probability distribution object

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描述

Aweibulldistributionobject consists of parameters, a model description, and sample data for a Weibull probability distribution.

Weibull分布用于可靠性和寿命建模，并为材料的破裂强度建模。

The Weibull distribution uses the following parameters.

Parameter 描述 金宝app
a 比例参数 a > 0
b Shape parameter b > 0

创建对象

统计和机器学习工具箱™ provides several ways to create aweibulldistributionprobability distribution object.

  • Create aWeibulllDistributionobject with specified parameter values usingmakedist.

    PD= makedist('Weibull')creates aweibulldistributionobject using the default parameter values for the scale parameter (a = 1）和形状参数（b = 1）。

    PD= makedist（'weibull'，'a'，a,'b',b)creates aweibulldistribution使用指定的参数值对象a和b.

    有关其他语法选项，请参阅makedist.

  • 适合weibulldistribution使用数据对象使用fitdist.

    PD= fitdist（x,'Weibull')creates aweibulldistributionobject by fitting a Weibull distribution to the data contained in the column vector,x.

    有关其他语法选项，请参阅fitdist.

  • Interactively fit aweibulldistribution使用数据对象使用the Distribution Fitter app,DistributionFitter.

Properties

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比例参数of the Weibull distribution, stored as a positive scalar value.

Data Types:single|双倍的

Weibull分布的形状参数，存储为正标量值。

Data Types:single|双倍的

Probability distribution name, stored as a character vector. This property is read-only.

Data Types:char

Data used for distribution fitting, stored as a structure containing the following:

  • 数据：用于分配拟合的数据向量。

  • Cens: Censoring vector, or empty if none.

  • freq: Frequency vector, or empty if none.

此属性仅阅读。

Data Types:struct

截断分布的逻辑标志，以逻辑值存储。如果IsTruncated等于0，分布没有截断。如果IsTruncated等于1，分布被截断。此属性仅阅读。

Data Types:logical

参数数for the probability distribution, stored as a positive integer value. This property is read-only.

Data Types:single|双倍的

参数估计的协方差矩阵，存储为一个p-经过-p矩阵，哪里pis the number of parameters in the distribution. The (i,j）元素是估计值之间的协方差ith parameter and thej参数。The (i,i）元素是估计的差异i参数。如果参数i是固定而不是通过将分布拟合到数据而估计的，然后i,i) elements of the covariance matrix are 0. This property is read-only.

Data Types:single|双倍的

Distribution parameter descriptions, stored as a cell array of character vectors. Each cell contains a short description of one distribution parameter. This property is read-only.

Data Types:char

固定参数的逻辑标志，存储为逻辑值的数组。如果0，在参数名称array is not fixed. If1，在参数名称array is fixed. This property is read-only.

Data Types:logical

分布参数名称, stored as a cell array of character vectors. This property is read-only.

Data Types:char

分布参数值，存储为向量。此属性仅阅读。

Data Types:single|双倍的

Truncation interval for the probability distribution, stored as a vector containing the lower and upper truncation boundaries. This property is read-only.

Data Types:single|双倍的

Object Functions

cdf 累积分布函数
ICDF Inverse cumulative distribution functions
iqr Interquartile range
意思是 概率分布的平均值
median Median of probability distribution
negloglik Negative log likelihood of probability distribution
paramci Confidence intervals for probability distribution parameters
PDf Probability density functions
proflik 概率的概率分布功能
random Random numbers
std 概率分布的标准偏差
truncate Truncate probability distribution object
var 概率分布的差异

例子

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打开脚本

Create a Weibull distribution object using the default parameter values.

PD= makedist('weibull')
PD= WeibullDistribution Weibull distribution A = 1 B = 1
打开脚本

Create a Weibull distribution object by specifying the parameter values.

PD= makedist('weibull','a'，2，'b'，5）
PD= WeibullDistribution Weibull distribution A = 2 B = 5

计算分布的平均值。

m = mean(pd)
M = 1.8363

See Also

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Topics

在R2013a中引入

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