Rank per row over multiple columns in R

Question

I'm using R for the analysis of my masterthesis. Unfortunately, I got stuck with this problem:

I would like to compute a new variable which calculates the rank of one variable per row within many variables.

Example:

V1    V2    V3   NewVariable_V1 NewVariable_V2 NewVariable_V3
11    21    35   3              2               1
22    12    66   2              3               1
44    22    12   1              2               3

Answer 1

You're looking for rank. To get decreasing order, first negate the data.frame.

data.frame(d, t(apply(-d, 1, rank, ties.method='min')))
#   V1 V2 V3 V1.1 V2.1 V3.1
# 1 11 21 35    3    2    1
# 2 22 12 66    2    3    1
# 3 44 22 12    1    2    3