CODEWITHSUNDEEP
rcategorical-data
gregorp
gregorp

Reputation: 285

Compare factor levels in R

I have a question regarding factors in R. Is there a way to compare the levels of each factor? I am interested in whether a level of one factor is a subset of a level of another factor. For example, let's say we have a vector:

a <- c(1,1,2,2,3,3,4,4,4)
a1 <- cut(a, breaks=c(1,2,3,4), include.lowest=TRUE)
a2 <- cut(a, breaks=c(1,3,4), include.lowest=TRUE)

levels(a1)
[1] "[1,2]" "(2,3]" "(3,4]"
levels(a2)
"[1,3]" "(3,4]"

So the first level of a2 includes the first two levels of a1. I need to know all such relations in some data. Is there a function in R which would give me all such combinations? Or at least a way to manually compare levels of a factor (extract breaks maybe), so I could write a function that does that? For now I've only done it with comparing the names of the levels, but that's not really efficient, since I usually don't have labels set at intervals.

Upvotes: 0

Views: 2020

Answers (1)

rnso
rnso

Reputation: 24535

I think you are looking for table function: 

> table(a1, a2)
       a2
a1      [1,3] (3,4]
  [1,2]     4     0
  (2,3]     2     0
  (3,4]     0     3

Upvotes: 1

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