muscle(MASS)
muscle()所属R语言包：MASS
Effect of Calcium Chloride on Muscle Contraction in Rat Hearts
氯化钙对大鼠心脏肌肉收缩
译者：生物统计家园网 机器人LoveR
描述----------Description----------
The purpose of this experiment was to assess the influence of calcium in solution on the contraction of heart muscle in rats. The left auricle of 21 rat hearts was isolated and on several occasions a constant-length strip of tissue was electrically stimulated and dipped into various concentrations of calcium chloride solution, after which the shortening of the strip was accurately measured as the response.
这个实验的目的是评估在大鼠心脏肌肉的收缩钙的溶液中的影响。 21大鼠心脏的左心房隔离，并多次对一个组织不断长条电刺激成不同浓度的氯化钙溶液，之后缩短带钢准确地测量响应蘸。
用法----------Usage----------
muscle
格式----------Format----------
This data frame contains the following columns:
这个数据框包含下列资料：
which heart muscle strip was used?
其中心脏肌肉带？
concentration of calcium chloride solution, in multiples of 2.2 mM.
浓度的氯化钙溶液，2.2毫米的倍数。
the change in length (shortening) of the strip, (allegedly) in mm.
长度变化（缩短）的地带，毫米（据称）。
源----------Source----------
Linder, A., Chakravarti, I. M. and Vuagnat, P. (1964) Fitting asymptotic regression curves with different asymptotes. In Contributions to Statistics. Presented to Professor P. C. Mahalanobis on the occasion of his 70th birthday, ed. C. R. Rao, pp. 221–228. Oxford: Pergamon Press.
林德，A.，查克拉瓦提，IM和Vuagnat，P.（1964）不同渐近渐近回归拟合曲线。在统计的贡献。提交给教授的PC版，他70岁生日之际马氏。 C.河饶，第221-228页。牛津：Pergamon出版社。
参考文献----------References----------
Modern Applied Statistics with S. Fourth Edition. Springer.
举例----------Examples----------
A <- model.matrix(~ Strip - 1, data=muscle)
rats.nls1 <- nls(log(Length) ~ cbind(A, rho^Conc),
data = muscle, start = c(rho=0.1), algorithm="plinear")
B <- coef(rats.nls1)
B
st <- list(alpha = B[2:22], beta = B[23], rho = B[1])
(rats.nls2 <- nls(log(Length) ~ alpha[Strip] + beta*rho^Conc,
data = muscle, start = st))
attach(muscle)
Muscle <- expand.grid(Conc = sort(unique(Conc)), Strip = levels(Strip))
Muscle$Yhat <- predict(rats.nls2, Muscle)
Muscle <- cbind(Muscle, logLength = rep(as.numeric(NA), 126))
ind <- match(paste(Strip, Conc),
paste(Muscle$Strip, Muscle$Conc))
Muscle$logLength[ind] <- log(Length)
detach()
require(lattice)
xyplot(Yhat ~ Conc | Strip, Muscle, as.table = TRUE,
ylim = range(c(Muscle$Yhat, Muscle$logLength), na.rm = TRUE),
subscripts = TRUE, xlab = "Calcium Chloride concentration (mM)",
ylab = "log(Length in mm)", panel =
function(x, y, subscripts, ...) {
lines(spline(x, y))
panel.xyplot(x, Muscle$logLength[subscripts], ...)
})
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。
注3：如遇到不准确之处，请在本贴的后面进行回帖，我们会逐渐进行修订。
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发表于 2012-2-16 20:35:09
