How can I shuffle the rows of two columns of a data frame object in R, keeping the rest of the columns the same? The shuffled rows of the columns should be linked, this means that both row values need to be shuffled together, not independently.
y <- c(18, 0, 2, 0, 0, 0, 2, 0, 0, 1, 7, 0, 0, 0, 0, 0, 0, 0, 0)
x1 <- c(501, 1597, 1156, 1134, 1924, 507, 1022, 0, 92, 1729, 85, 963, 544, 1315, 2250, 1366, 458, 385, 930)
x2 <- c(0, 92, 959, 1146, 900, 0, 276, 210, 980, 8, 0, 473, 0, 255, 1194, 542, 983, 331, 923)
offset_1 <- c(59, 34, 33, 35, 60, 58, 59, 33, 34, 61, 58, 58, 55, 26, 26, 18, 26, 26, 26)
data_1 <- data.frame(y,x1,x2,offset_1)
In this example I want to shuffle the rows of 'y' and 'offset_1' together, keeping the rest of the columns the same.
You can reshuffle the rows using sample on the selected columns:
set.seed(1)
cols = c("y", "offset_1")
data_1[cols] <- data_1[sample(nrow(data_1)), cols]
output
# y x1 x2 offset_1
# 1 0 501 0 35
# 2 2 1597 92 59
# 3 18 1156 959 59
# 4 0 1134 1146 34
# 5 0 1924 900 55
# 6 0 507 0 26
# 7 7 1022 276 58
# 8 0 0 210 18
# 9 0 92 980 26
# 10 2 1729 8 33
# 11 0 85 0 26
# 12 0 963 473 60
# 13 0 544 0 33
# 14 0 1315 255 58
# 15 0 2250 1194 58
# 16 1 1366 542 61
# 17 0 458 983 34
# 18 0 385 331 26
# 19 0 930 923 26