Beta(stats)
Beta()所属R语言包:stats
The Beta Distribution
Beta分布
译者:生物统计家园网 机器人LoveR
描述----------Description----------
Density, distribution function, quantile function and random generation for the Beta distribution with parameters shape1 and shape2 (and optional non-centrality parameter ncp).
密度,分布函数,分位数函数和Beta分布参数的随机生成shape1和shape2(和可选的非核心参数ncp)。
用法----------Usage----------
dbeta(x, shape1, shape2, ncp = 0, log = FALSE)
pbeta(q, shape1, shape2, ncp = 0, lower.tail = TRUE, log.p = FALSE)
qbeta(p, shape1, shape2, ncp = 0, lower.tail = TRUE, log.p = FALSE)
rbeta(n, shape1, shape2, ncp = 0)
参数----------Arguments----------
参数:x, q
vector of quantiles.
位数的向量。
参数:p
vector of probabilities.
概率向量。
参数:n
number of observations. If length(n) > 1, the length is taken to be the number required.
观测数。如果length(n) > 1,长度是所需的数量。
参数:shape1, shape2
positive parameters of the Beta distribution.
Beta分布的积极参数。
参数:ncp
non-centrality parameter.
非核心参数。
参数:log, log.p
logical; if TRUE, probabilities p are given as log(p).
逻辑;如果为TRUE,概率P日志(P)。
参数:lower.tail
logical; if TRUE (default), probabilities are P[X ≤ x], otherwise, P[X > x].
逻辑;如果是TRUE(默认),概率P[X ≤ x],否则,“P[X > x]。
Details
详情----------Details----------
The Beta distribution with parameters shape1 = a and shape2 = b has density
Beta分布参数shape1= a和shape2= b有密度
for a > 0, b > 0 and 0 ≤ x ≤ 1 where the boundary values at x=0 or x=1 are defined as by continuity (as limits). <br> The mean is a/(a+b) and the variance is ab/((a+b)^2 (a+b+1)).
a > 0,b > 0和0 ≤ x ≤ 1其中x=0或x=1连续性(限制)定义的边界值。 <BR>平均a/(a+b)和方差是ab/((a+b)^2 (a+b+1))。
pbeta is closely related to the incomplete beta function. As defined by Abramowitz and Stegun 6.6.1
pbeta密切相关的完整的测试功能。由Abramowitz和Stegun 6.6.1的定义
and 6.6.2 I_x(a,b) = B_x(a,b) / B(a,b) where B(a,b) = B_1(a,b) is the Beta function (beta).
6.6.2I_x(a,b) = B_x(a,b) / B(a,b)其中B(a,b) = B_1(a,b)是Beta函数(beta)。
I_x(a,b) is pbeta(x,a,b).
I_x(a,b)是pbeta(x,a,b)。
The noncentral Beta distribution (with ncp = λ) is defined (Johnson et al, 1995, pp. 502) as the distribution of X/(X+Y) where X ~ chi^2_2a(λ) and Y ~ chi^2_2b.
在非中心Beta分布(用ncp = λ)定义(约翰逊等人,1995年,页502)作为X/(X+Y)其中X ~ chi^2_2a(λ)和Y ~ chi^2_2b分布。
值----------Value----------
dbeta gives the density, pbeta the distribution function, qbeta the quantile function, and rbeta generates random deviates.
dbeta给人的密度,pbeta分布函数,qbeta位数的功能,和rbeta生成随机的偏离。
Invalid arguments will result in return value NaN, with a warning.
无效的参数将导致返回值NaN,一个警告。
注意----------Note----------
Supplying ncp = 0 uses the algorithm for the non-central distribution, which is not the same algorithm used if ncp is omitted. This is to give consistent behaviour in extreme cases with values of ncp very near zero.
供应ncp = 0使用算法的非中心分布,这是不使用相同的算法,如果ncp省略。这是给予一致的行为,在极端情况下ncp非常接近零值。
源----------Source----------
The central dbeta is based on a binomial probability, using code contributed by Catherine Loader (see dbinom) if either shape parameter is larger than one, otherwise directly from the definition. The non-central case is based on the derivation as a Poisson mixture of betas (Johnson et al, 1995, pp. 502–3).
中央dbeta是基于二项式概率,使用由凯瑟琳装载机贡献的代码(见dbinom)如果任一形状参数大于1,否则直接从定义。基于非中央的情况下作为一个beta版的泊松混合(Johnson等,1995年,第502-3页)的推导。
The central pbeta uses a C translation (and enhancement for log_p=TRUE) of
中央pbeta使用(log_p=TRUE的和增强的C)的翻译
Didonato, A. and Morris, A., Jr, (1992) Algorithm 708: Significant digit computation of the incomplete beta function ratios, ACM Transactions on Mathematical Software, 18, 360–373. (See also<br> Brown, B. and Lawrence Levy, L. (1994) Certification of algorithm 708: Significant digit computation of the incomplete beta, ACM Transactions on Mathematical Software, 20, 393–397.)
didonato,A.和莫里斯,JR(1992)708算法显着完整的测试功能比数字计算,数学软件,18,360-373 ACM交易。 (见参考布朗,B和劳伦斯·利维,L.(1994)认证算法708。重大的不完全β数字计算,ACM交易在数学软件,20,393-397)
The non-central pbeta uses a C translation of
非中央pbeta使用的C翻译
Lenth, R. V. (1987) Algorithm AS226: Computing noncentral beta probabilities. Appl. Statist, 36, 241–244, incorporating<br> Frick, H. (1990)'s AS R84, Appl. Statist, 39, 311–2, and<br> Lam, M.L. (1995)'s AS R95, Appl. Statist, 44, 551–2.
全长,RV(1987)AS226算法:计算非中心测试的概率。应用中央集权,36,241-244,纳入R84参考弗里克,H.(1990)“,APPL。中央集权,39,311-2,并参考林,M.L. (1995年)的R95,APPL。中央集权,44,551-2。
This computes the lower tail only, so the upper tail suffers from cancellation and a warning will be given when this is likely to be significant.
这仅计算较低的尾巴,所以尾巴上遭受取消时,这是很大的,将给予警告。
The central case of qbeta is based on a C translation of
中央的情况下qbeta是基于一个C翻译
Cran, G. W., K. J. Martin and G. E. Thomas (1977). Remark AS R19 and Algorithm AS 109, Applied Statistics, 26, 111–114, and subsequent remarks (AS83 and correction).
CRAN,毛重,KJ马丁公司和通用电气托马斯(1977)。备注AS R19和AS 109算法,应用统计,26,111-114,和随后的发言(AS83和校正)。
The central case of rbeta is based on a C translation of
中央的情况下rbeta是基于一个C翻译
R. C. H. Cheng (1978). Generating beta variates with nonintegral shape parameters. Communications of the ACM, 21, 317–322.
河C. H.程(1978)。贝塔分布随机产生非整数的形状参数。通信的ACM,21,317-322。
参考文献----------References----------
The New S Language. Wadsworth & Brooks/Cole.
Handbook of Mathematical Functions. New York: Dover. Chapter 6: Gamma and Related Functions.
Continuous Univariate Distributions, volume 2, especially chapter 25. Wiley, New York.
参见----------See Also----------
Distributions for other standard distributions.
其他标准分布的分布。
beta for the Beta function.
betaBeta函数。
举例----------Examples----------
x <- seq(0, 1, length=21)
dbeta(x, 1, 1)
pbeta(x, 1, 1)
转载请注明:出自 生物统计家园网(http://www.biostatistic.net)。
注:
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