lirat(VGAM)
lirat()所属R语言包：VGAM
Low-iron Rat Teratology Data
低铁大鼠致畸胎数据
译者：生物统计家园网 机器人LoveR
描述----------Description----------
Low-iron rat teratology data.
低铁大鼠致畸性的数据。
用法----------Usage----------
data(lirat)
格式----------Format----------
A data frame with 58 observations on the following 4 variables.
58观察以下4个变量的数据框。
N Litter size.
N产仔数。
R Number of dead fetuses.
R死胎数。
hb Hemoglobin level.
hb的血红蛋白水平。
grp Group number. Group 1 is the untreated (low-iron) group, group 2 received injections on day 7 or day 10 only, group 3 received injections on days 0 and 7, and
grp组号码。组1是未经处理的（低铁）的组，第2组接受注射的第7天或天10只，第3组接受注射第0和7天，并
Details
详细信息----------Details----------
The following description comes from Moore and Tsiatis (1991). The data comes from the experimental setup from Shepard et al. (1980), which is typical of studies of the effects of chemical agents or dietary regimens on fetal development in laboratory rats.
下面的描述从摩尔和Tsiatis的（1991）。数据来自谢泼德等人的实验装置。 （1980年），这是典型的化学物质或饮食处方，在实验室老鼠胎儿的发育的影响的研究。
Female rats were put in iron-deficient diets and divided into 4 groups. One group of controls was given weekly injections of iron supplement to bring their iron intake to normal levels, while another group was given only placebo injections. Two other groups were given fewer iron-supplement injections than the controls. The rats were made pregnant, sacrificed 3 weeks later, and the total number of fetuses and the number of dead fetuses in each litter were counted.
缺铁饮食雌性大鼠分为4组。一组控件每周注射补铁，铁的摄入，使他们的正常水平，而另一组只服用安慰剂注射。另外两个组比对照组少的铁补充注射。大鼠怀孕3周后，牺牲，并在每个垃圾总数的胎儿和死胎的数量进行计数。
For each litter the number of dead fetuses may be considered to be Binomial(N,p) where N is the litter size and p is the probability of a fetus dying. The parameter p is expected to vary from litter to litter, therefore the total variance of the proportions will be greater than that predicted by a binomial model, even when the covariates for hemoglobin level and experimental group are accounted for.
每窝死胎数，可能会被认为是二项（N,p），其中N是窝产仔数和p是胎儿死亡的概率。参数p预计因乱抛垃圾乱扔垃圾，因此总方差的比例将有更大的比二项式模型预测，即使当协变量的血红蛋白水平和实验组占。
源----------Source----------
Moore, D. F. and Tsiatis, A. (1991) Robust Estimation of the Variance in Moment Methods for Extra-binomial and Extra-Poisson Variation. Biometrics, 47, 383–401.
摩尔，DF和Tsiatis的，A.（1991）稳健估计的额外二项式和额外的泊松变化的方差矩量法。生物识别技术，47，383-401。
参考文献----------References----------
Reproductive studies in the iron-deficient rat. Teratology, 22, 329–334.
实例----------Examples----------
## Not run: [＃不运行：]
# cf. Figure 3 of Moore and Tsiatis (1991)[比照。图3 Moore和Tsiatis的（1991）]
plot(R/N ~ hb, data = lirat, pch = as.character(grp), col = grp,
las = 1, xlab = "Hemoglobin level", ylab = "Proportion Dead")
## End(Not run)[＃（不执行）]
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 2012-10-1 15:41:15
