我想做以下事情并需要一些帮助:
分别计算“年龄”[lm(高度〜年龄)]的“高度”的斜率和截距
(A)每个人
(B)性别
并创建一个包含结果(斜率和截距)的表。我可以使用“申请”吗?
在下一步中,我想做一个统计测试,以确定性别之间的斜率和截距是否有显着差异。我知道如何在R中进行测试,但也许有一种方法可以将斜率/截距计算和T检验结合起来。
示例数据:
example = data.frame(Age = c(1, 3, 6, 9, 12,
1, 3, 6, 9, 12,
1, 3, 6, 9, 12,
1, 3, 6, 9, 12),
Individual = c("Jack", "Jack", "Jack", "Jack", "Jack",
"Jill", "Jill", "Jill", "Jill", "Jill",
"Tony", "Tony", "Tony", "Tony", "Tony",
"Jen", "Jen", "Jen", "Jen","Jen"),
Gender = c("M", "M", "M", "M", "M",
"F", "F", "F", "F", "F",
"M", "M", "M", "M", "M",
"F", "F", "F", "F", "F"),
Height = c(38, 62, 92, 119, 165,
31, 59, 87, 118, 170,
45, 72, 93, 155, 171,
33, 61, 92, 115, 168))
答案 0 :(得分:5)
对每个级别分别进行回归分析,然后在数据框中组合斜率和截距的一种方法是使用库ddply()
中的函数plyr
。
library(plyr)
ddply(example,"Individual",function(x) coefficients(lm(Height~Age,x)))
Individual (Intercept) Age
1 Jack 26.29188 11.11421
2 Jen 22.10660 11.56345
3 Jill 18.33249 12.04315
4 Tony 33.02030 11.96447
ddply(example,"Gender",function(x) coefficients(lm(Height~Age,x)))
Gender (Intercept) Age
1 F 20.21954 11.80330
2 M 29.65609 11.53934