描述:如果以 1 小时的间隔(1,2...10)测量六个对象(obj_A、obj_B、...obj_F)的温度。对象受到两种处理(A 和 B)的影响。治疗A = obj_A,obj_B,obj_C;治疗 B = obj_D,obj_E,obj_F。
问题是每个对象的测量值是序列相关的,因此我不能使用经典 的方差分析。如何考虑这样的事实?
# example data
my.data <- data.frame(object = rep(c("obj_A","obj_B","obj_C",
"obj_D","obj_E","obj_F"),
each = 10),
time = rep(c(1:10), times = 6),
treatment = rep(c("A","B"), each = 30),
value = c(4,4,7,8,8,10,8,12,14,12,
8,8,12,12,10,12,10,11,12,16,
12,12,11,13,12,16,16,14,16,20,
11,20,23,27,31,29,31,32,28,30,
12,16,17,23,22,24,33,31,31,32,
14,13,19,20,24,26,24,28,25,23))
# converting values to time series object
obj_A <- ts(my.data$value[my.data$object=="obj_A"],
start = 1, end = 10, frequency = 1)
obj_B <- ts(my.data$value[my.data$object=="obj_B"],
start = 1, end = 10, frequency = 1)
obj_C <- ts(my.data$value[my.data$object=="obj_C"],
start = 1, end = 10, frequency = 1)
obj_D <- ts(my.data$value[my.data$object=="obj_D"],
start = 1, end = 10, frequency = 1)
obj_E <- ts(my.data$value[my.data$object=="obj_E"],
start = 1, end = 10, frequency = 1)
obj_F <- ts(my.data$value[my.data$object=="obj_F"],
start = 1, end = 10, frequency = 1)
# plot -> blue = treatment A; red = treatment B
ts.plot(obj_A, obj_B, obj_C, obj_D, obj_E, obj_F,
col=c("deepskyblue","deepskyblue1","deepskyblue2",
"darkred","indianred","indianred1"),
lwd = 2.5, lty = 2, xlab = "time", ylab = "temperature")
如何严格测试对象的温度是否因使用的处理而不同,但又不忽略序列相关性?