logff(VGAM)
logff()所属R语言包：VGAM
Logarithmic Distribution
对数分布
译者：生物统计家园网 机器人LoveR
描述----------Description----------
Estimating the (single) parameter of the logarithmic distribution.
（单）的对数分布的参数估计。
用法----------Usage----------
logff(link = "logit", earg=list(), init.c = NULL)
参数----------Arguments----------
参数：link
Parameter link function applied to the parameter c, which lies between 0 and 1. See Links for more choices.
参数施加到参数c，它位于0和1之间的链接功能。见Links更多的选择。
参数：earg
List. Extra argument for the link. See earg in Links for general information.
列表。额外的参数的链接。见earg中Links的一般信息。
参数：init.c
Optional initial value for the c parameter. If given, it often pays to start with a larger value, e.g., 0.95. The default is to choose an initial value internally.
可选c参数的初始值。如果给定的，它往往支付一个较大的值，例如，0.95开始。默认值是内部选择一个初始值。
Details
详细信息----------Details----------
The logarithmic distribution is based on the logarithmic series, and is scaled to a probability function. Its probability function is f(y) = a * c^y / y, for y=1,2,3,..., where 0 < c < 1, and a = -1 / log(1-c). The mean is a*c/(1-c) (returned as the fitted values) and variance is a*c*(1-a*c)/(1-c)^2.
是根据对数系列的对数分布，并进行缩放，以概率函数。它的概率函数是f(y) = a * c^y / y，y=1,2,3,...，在那里0 < c < 1，a = -1 / log(1-c)。的平均a*c/(1-c)（返回的拟合值）和方差是a*c*(1-a*c)/(1-c)^2。
值----------Value----------
An object of class "vglmff" (see vglmff-class). The object is used by modelling functions such as vglm, and vgam.
类的一个对象"vglmff"（见vglmff-class）。该对象被用于建模功能，如vglm，vgam。
注意----------Note----------
The function log computes the natural logarithm. In the VGAM library, a link function with option loge corresponds to this.
的功能log计算自然对数。在VGAM库，链接功能选项“loge对应了这一点。
The logarithmic distribution is sometimes confused with the log-series distribution. The latter was used by Fisher et al. for species abundance data, and has two parameters.
对数分布是有时混淆的log序列分布。后者使用了由Fisher等人。物种丰度数据，并有两个参数。
（作者）----------Author(s)----------
T. W. Yee
参考文献----------References----------
Johnson N. L., Kemp, A. W. and Kotz S. (2005) Univariate Discrete Distributions, 3rd edition, Hoboken, New Jersey: Wiley.
Statistical Distributions, New York: Wiley-Interscience, Third edition.
参见----------See Also----------
rlog, log, loge, logoff, explogarithmic.
rlog，log，loge，logoff，explogarithmic。
实例----------Examples----------
ldata = data.frame(y = rlog(n = 1000, prob = logit(0.2, inverse = TRUE)))
fit = vglm(y ~ 1, logff, ldata, trace = TRUE, crit = "c")
coef(fit, matrix = TRUE)
Coef(fit)
## Not run: with(ldata,[＃不运行（的ldata]
hist(y, prob = TRUE, breaks = seq(0.5, max(y) + 0.5, by = 1),
border = "blue"))
x = seq(1, with(ldata, max(y)), by=1)
with(ldata, lines(x, dlog(x, Coef(fit)[1]), col = "orange", type = "h", lwd = 2))
## End(Not run)[＃（不执行）]
# Example: Corbet (1943) butterfly Malaya data[例：科比特（1943）蝴蝶马来亚数据]
corbet = data.frame(nindiv = 1:24,
ofreq = c(118, 74, 44, 24, 29, 22, 20, 19, 20, 15, 12,
14, 6, 12, 6, 9, 9, 6, 10, 10, 11, 5, 3, 3))
fit = vglm(nindiv ~ 1, logff, data = corbet, weights = ofreq)
coef(fit, matrix = TRUE)
chat = Coef(fit)["c"]
pdf2 = dlog(x = with(corbet, nindiv), prob = chat)
print(with(corbet, cbind(nindiv, ofreq, fitted = pdf2 * sum(ofreq))), dig = 1)
转载请注明:出自 生物统计家园网(http://www.biostatistic.net)。
注：
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发表于 2012-10-1 15:41:55
