18 lines
475 B
R
18 lines
475 B
R
|
# Goal: To do sorting.
|
||
|
|
#
|
||
|
|
# The approach here needs to be explained. If `i' is a vector of
|
||
|
|
# integers, then the data frame D[i,] picks up rows from D based
|
||
|
|
# on the values found in `i'.
|
||
|
|
#
|
||
|
|
# The order() function makes an integer vector which is a correct
|
||
|
|
# ordering for the purpose of sorting.
|
||
|
|
|
||
|
|
D <- data.frame(x=c(1,2,3,1), y=c(7,19,2,2))
|
||
|
|
D
|
||
|
|
|
||
|
|
# Sort on x
|
||
|
|
indexes <- order(D$x)
|
||
|
|
D[indexes,]
|
||
|
|
|
||
|
|
# Print out sorted dataset, sorted in reverse by y
|
||
|
|
D[rev(order(D$y)),]
|