norm.ci(boot)
norm.ci()所属R语言包：boot
Normal Approximation Confidence Intervals
正态近似置信区间
译者：生物统计家园网 机器人LoveR
描述----------Description----------
Using the normal approximation to a statistic, calculate equi-tailed two-sided confidence intervals.
使用正常的近似一个统计，计算等尾双面置信区间。
用法----------Usage----------
norm.ci(boot.out = NULL, conf = 0.95, index = 1, var.t0 = NULL,
t0 = NULL, t = NULL, L = NULL, h = function(t) t,
hdot = function(t) 1, hinv = function(t) t)
参数----------Arguments----------
参数：boot.out
A bootstrap output object returned from a call to boot. If t0 is missing then boot.out is a required argument. It is also required if both var.t0 and t are missing.
调用boot从引导输出对象返回。如果t0缺少boot.out是一个必需的参数。它也要求，如果这两个var.t0和t失踪。
参数：conf
A scalar or vector containing the confidence level(s) of the required interval(s).
包含的信心水平所需的时间间隔（S）（S）的一个标量或矢量。
参数：index
The index of the statistic of interest within the output of a call to boot.out$statistic. It is not used if boot.out is missing, in which case t0 must be supplied.
内的输出调用boot.out$statistic一个利益的统计指标。不使用它，如果boot.out丢失，在这种情况下t0必须提供。
参数：var.t0
The variance of the statistic of interest. If it is not supplied then var(t) is used.
利益的统计方差。如果没有提供，则var(t)使用。
参数：t0
The observed value of the statistic of interest. If it is missing then it is taken from boot.out which is required in that case.
利益的统计观测值。如果它丢失了，那么它是取自boot.out这是在这种情况下所必需的。
参数：t
Bootstrap replicates of the variable of interest. These are used to estimate the variance of the statistic of interest if var.t0 is not supplied. The default value is boot.out$t[,index].
引导复制的变量。这些被用来估计var.t0如果不提供利益的统计方差。默认值是boot.out$t[,index]。
参数：L
The empirical influence values for the statistic of interest. These are used to calculate var.t0 if neither var.t0 nor boot.out are supplied. If a transformation is supplied through h then the influence values must be for the untransformed statistic t0.
利益的统计经验的影响值。这些被用来计算var.t0如果没有var.t0也boot.out提供。如果转型提供h进而影响值必须是未转换的统计t0。
参数：h
A function defining a monotonic transformation, the intervals are calculated on the scale of h(t) and the inverse function hinv is applied to the resulting intervals. h must be a function of one variable only and must be vectorized. The default is the identity function.
一个功能定义单调转型，间隔计算规模h(t)和反函数hinv应用所产生的间隔。 h必须是一个变量的函数，必须量化。默认是身份的功能。
参数：hdot
A function of one argument returning the derivative of h. It is a required argument if h is supplied and is used for approximating the variance of h(t0). The default is the constant function 1.
一个一个参数返回h衍生功能。 h如果提供用于逼近h(t0)方差，这是一个必要的参数。默认是恒定的功能1。
参数：hinv
A function, like h, which returns the inverse of h. It is used to transform the intervals calculated on the scale of h(t) back to the original scale. The default is the identity function. If h is supplied but hinv is not, then the intervals returned will be on the transformed scale.
一个函数，返回像h，逆h。它使用转换h(t)回原有规模的规模计算的时间间隔。默认是身份的功能。 h如果提供，但hinv是不是，那么返回的时间间隔将规模转化。
Details
详情----------Details----------
It is assumed that the statistic of interest has an approximately normal distribution with variance var.t0 and so a confidence interval of length 2*qnorm((1+conf)/2)*sqrt(var.t0) is found. If boot.out or t are supplied then the interval is bias-corrected using the bootstrap bias estimate, and so the interval would be centred at 2*t0-mean(t). Otherwise the interval is centred at t0.
据推测，利益的统计数据有一个近似正态分布方差var.t0和置信区间的长度2*qnorm((1+conf)/2)*sqrt(var.t0)被发现。如果boot.out或t提供的时间间隔是偏见，纠正使用自举偏置估计，这样的间隔将在2*t0-mean(t)中心。否则间隔集中在t0。
值----------Value----------
If length(conf) is 1 then a vector containing the confidence level and the endpoints of the interval is returned. Otherwise, the returned value is a matrix where each row corresponds to a different confidence level.
length(conf)如果1，然后返回一个向量包含的信心水平和间隔端点。否则，返回值是一个矩阵，其中的每一行对应到不同的置信水平。
注意----------Note----------
This function is primarily designed to be called by boot.ci to calculate the normal approximation after a bootstrap but it can also be used without doing any bootstrap calculations as long as t0 and var.t0 can be supplied. See the examples below.
此功能主要是设计来boot.ci称为计算后，引导正常的近似，但它也可以，只要没有做任何引导计算为t0和var.t0可提供。见下面的例子。
参考文献----------References----------
Bootstrap Methods and Their Application. Cambridge University Press.
参见----------See Also----------
boot.ci
boot.ci
举例----------Examples----------
# In Example 5.1 of Davison and Hinkley (1997), normal approximation [在戴维森和欣克利（1997），近似正常的范例5.1]
# confidence intervals are found for the air-conditioning data.[置信区间为空调数据。]
air.mean <- mean(aircondit$hours)
air.n <- nrow(aircondit)
air.v <- air.mean^2/air.n
norm.ci(t0 = air.mean, var.t0 = air.v)
exp(norm.ci(t0 = log(air.mean), var.t0 = 1/air.n)[2:3])
# Now a more complicated example - the ratio estimate for the city data.[现在一个比较复杂的例子 - 城市数据的比例估计。]
ratio <- function(d, w)
sum(d$x * w)/sum(d$u *w)
city.v <- var.linear(empinf(data = city, statistic = ratio))
norm.ci(t0 = ratio(city,rep(0.1,10)), var.t0 = city.v)
转载请注明:出自 生物统计家园网(http://www.biostatistic.net)。
注：
注1：为了方便大家学习，本文档为生物统计家园网机器人LoveR翻译而成，仅供个人R语言学习参考使用，生物统计家园保留版权。
注2：由于是机器人自动翻译，难免有不准确之处，使用时仔细对照中、英文内容进行反复理解，可以帮助R语言的学习。
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发表于 2012-2-16 18:27:09
