函数介绍
t.test(x, y = NULL,
alternative = c("two.sided", "less", "greater"),
mu = 0, paired = FALSE, var.equal = FALSE,
conf.level = 0.95, ...)
Value
A list with class "htest" containing the following components:
| statistic | the value of the t-statistic. |
| parameter | the degrees of freedom for the t-statistic. |
| p.value | the p-value for the test. |
| conf.int | a confidence interval for the mean appropriate to the specified alternative hypothesis. |
| estimate | the estimated mean or difference in means depending on whether it was a one-sample test or a two-sample test. |
| null.value | the specified hypothesized value of the mean or mean difference depending on whether it was a one-sample test or a two-sample test. |
| alternative | a character string describing the alternative hypothesis. |
| method | a character string indicating what type of t-test was performed. |
| data.name | a character string giving the name(s) of the data. |
例题：比较甲、乙两种安眠药地疗效，将20名患者分成两组，每组10人，分别服用甲、乙两种安眠药，获得相关数据表所列。一直服用两种安眠药后增加地睡眠时间服从方差相同地正态分布，且两组实验相互独立。显著性水平
＝0.05，试问两种安眠药地疗效有无显著差异？
| 类别 | 延长睡眠时间／小时 | |||||||||
| 服用甲种药 | 1.9 | 0.8 | 1.1 | 0.1 | 0.1 | 4.4 | 5.5 | 1.6 | 4.6 | 3.4 |
| 服用乙种药 | 0.7 | －1.6 | －0.2 | －1.2 | －0.1 | 3.4 | 3.7 | 0.8 | 0.0 | 2.0 |
分析：
相同时，假设检验为
；
#函数t.test()；
x<-c(1.9,0.8,1.1,0.1,0.1,4.4,5.5,1.6,4.6,3.4)
y<-c(0.7,-1.6,-0.2,-1.2,-0.1,3.4,3.7,0.8,0.0,2.0)
t.test(x,y)