R 为每个参与者的每个条件选择 n 行

Question

我有这个关于多个单一研究的数据框。对三名受试者(ID_AB2(实施了行为干预，并收集了基线和干预条件的数据(阶段AB2：A =基线;B = 干预(。最后，"Occassions"是一个包含会话编号的变量。

我试图做的是编写一个代码来获取每个参与者每个阶段的最后三个值，然后计算平均值。

RateAB2 <- c(8, 4, 5, 5, 5, 4, 8, 7, 8, 5, 4, 8, 7, 4, 7, 7, 4, 3, 4, 4, 4, 5, 9, 6, 16, 13, 8, 9, 15, 17, 9, 10, 7, 3, 2, 4, 3, 3, 3, 7, 13, 18, 12, 18, 14, 17, 19, 15) %>% as.numeric()
PhaseAB2 <- rep(c("A", "B"), each = 8, len = 48)
OccasionsAB2 <- rep(1:16, len = 48)
ID_AB2 <- rep(c("C1", "C2", "C3"), each = 16)
db5 <- data.frame(ID_AB2, OccasionsAB2, PhaseAB2, RateAB2)

我想使用dbdplyr::filter(OccasionsAB2 == ...)但代码将严格依赖于每个特定的数据集，并且它无法为具有不同观察数量的参与者选择不同的位置。

感谢您的任何帮助！

Answer 1

library(dplyr)
RateAB2 <- c(8, 4, 5, 5, 5, 4, 8, 7, 8, 5, 4, 
8, 7, 4, 7, 7, 4, 3, 4, 4, 4, 5, 
9, 6, 16, 13, 8, 9, 15, 17, 9, 
10, 7, 3, 2, 4, 3, 3, 3, 7, 13, 
18, 12, 18, 14, 17, 19, 15) %>% 
as.numeric()
PhaseAB2 <- rep(c("A", "B"), each = 8, len = 48)
OccasionsAB2 <- rep(1:16, len = 48)
ID_AB2 <- rep(c("C1", "C2", "C3"), each = 16)
db5 <- data.frame(ID_AB2, OccasionsAB2, PhaseAB2, RateAB2)
db5 %>%
group_by(ID_AB2, PhaseAB2) %>%       # for each ID and Phase
top_n(3, OccasionsAB2) %>%           # keep last 3 occasions
summarise(MEAN = mean(RateAB2)) %>%  # get the average
ungroup()                            # forget the grouping
# # A tibble: 6 x 3
#   ID_AB2 PhaseAB2  MEAN
#   <fct>  <fct>    <dbl>
# 1 C1     A         6.33
# 2 C1     B         6   
# 3 C2     A         6.67
# 4 C2     B        12   
# 5 C3     A         4.33
# 6 C3     B        17 

您可以将过去的summarise更新为

summarise(MEAN = mean(RateAB2), OccasionSequence = paste0(OccasionsAB2, collapse = ","))

还要获取每种情况下使用的场合的 ID(作为字符串(。