I have a categorical data set that looks similar to:
A < -data.frame(animal = c("cat","cat","cat","dog","dog","dog","elephant","elephant","elephant"),
color = c(rep(c("blue","red","green"), 3)))
animal color
1 cat blue
2 cat red
3 cat green
4 dog blue
5 dog red
6 dog green
7 elephant blue
8 elephant red
9 elephant green
I want to order it so that 'animal' is sorted as dog < elephant < cat
, and then the color is sorted green < blue < red
. So in the end it would look like
# animal color
# 6 dog green
# 4 dog blue
# 5 dog red
# 9 elephant green
# 7 elephant blue
# 8 elephant red
# 3 cat green
# 1 cat blue
# 2 cat red
The levels should be specified explicitly:
A$animal <- factor(A$animal, levels = c("dog", "elephant","cat"))
A$color <- factor(A$color, levels = c("green", "blue", "red"))
Then you order by the 2 columns simultaneously:
A[order(A$animal,A$color),]
# animal color
# 6 dog green
# 4 dog blue
# 5 dog red
# 9 elephant green
# 7 elephant blue
# 8 elephant red
# 3 cat green
# 1 cat blue
# 2 cat red