Не лучший способ, но он работает
x <- data.frame(c(rep(1,10), rep(2,10)), c(1,1,2,2,2,1,1,2,2,2,1,1,1,2,2,1,1,1,2,2), c(100,200,80,58,89,100,200,80,58,89,95,72,99,120,130,95,72,99,120,130))
colnames(x) <- c("ID", "Condition", "Y")
id <- unique(x[,1])
con <- unique(x[,2])
#multiple by the number of groups to split into
y <- data.frame(matrix(, ncol = (length(id) * 4) + 1, nrow = length(id)))
y[,1] <- id
colnames(y) <- c("ID", "Condition1M1", "Condition1M2", "Condition1M3", "Condition1M4", "Condition2M1", "Condition2M2", "Condition2M3", "Condition2M4")
x1 <- x[which(x[,2] == con[1]),]
x2 <- x[which(x[,2] == con[2]),]
#specify sample size
n <- 5
x11 <- x1[sample(nrow(x1), n, replace = FALSE),]
x12 <- x1[sample(nrow(x1), n, replace = FALSE),]
x13 <- x1[sample(nrow(x1), n, replace = FALSE),]
x14 <- x1[sample(nrow(x1), n, replace = FALSE),]
x21 <- x2[sample(nrow(x2), n, replace = FALSE),]
x22 <- x2[sample(nrow(x2), n, replace = FALSE),]
x23 <- x2[sample(nrow(x2), n, replace = FALSE),]
x24 <- x2[sample(nrow(x2), n, replace = FALSE),]
y[1,2] <- mean(x11[which(x11[,1] == id[1]),3])
y[1,3] <- mean(x12[which(x12[,1] == id[1]),3])
y[1,4] <- mean(x13[which(x13[,1] == id[1]),3])
y[1,5] <- mean(x14[which(x14[,1] == id[1]),3])
y[2,2] <- mean(x21[which(x21[,1] == id[2]),3])
y[2,3] <- mean(x22[which(x22[,1] == id[2]),3])
y[2,4] <- mean(x23[which(x23[,1] == id[2]),3])
y[2,5] <- mean(x24[which(x24[,1] == id[2]),3])
y[1,6] <- mean(x11[which(x11[,1] == id[1]),3])
y[1,7] <- mean(x12[which(x12[,1] == id[1]),3])
y[1,8] <- mean(x13[which(x13[,1] == id[1]),3])
y[1,9] <- mean(x14[which(x14[,1] == id[1]),3])
y[2,6] <- mean(x21[which(x21[,1] == id[2]),3])
y[2,7] <- mean(x22[which(x22[,1] == id[2]),3])
y[2,8] <- mean(x23[which(x23[,1] == id[2]),3])
y[2,9] <- mean(x24[which(x24[,1] == id[2]),3])
Результаты:
ID Condition1M1 Condition1M2 Condition1M3 Condition1M4 Condition2M1 Condition2M2 Condition2M3 Condition2M4
1 1 133.3333 100 150 133.3333 133.3333 100 150 133.3333
2 2 125.0000 125 125 120.0000 125.0000 125 125 120.0000