How to count entries with specific values in R

Question

Let's say I have two vectors

x <- c(1, 2, 2, 3, 4, 4, 5, 5, 5) 
y <- c(3, 3, 3, 4, 5, 6, 6, 7, 7)

The unique numbers among all the numbers in these vectors are 1:7. I know that if I use the table function in R, I can count the number of unique entries in each of the vectors. For example, if I apply the table function to the first vector, I will get

table(x)
#x
# 1 2 3 4 5 
# 1 2 1 2 3

Applying it to the second vector, I will get

table(y)
# y
# 3 4 5 6 7 
# 3 1 1 2 2

How can I get it to count the number of occurrences of all unique entries in both vectors? For example, I'd like to produce the following results:

1 2 3 4 5 6 7
1 2 1 2 3 0 0

for the first vector and

1 2 3 4 5 6 7
0 0 3 1 1 2 2

Why is the last two entries 0 in the first vector and first two 0 in second one? — akrun, Sep 21 '16 at 03:23

score 2 · Accepted Answer · answered Sep 21 '16 at 03:37

2

First, generate a list of the values you want to get counts for in both vectors

lvl<-unique(c(x,y))

Then explicitly list those values as levels of a factor before doing table

table(factor(x, lvl))
table(factor(y, lvl))

answered Sep 21 '16 at 03:37

MrFlick

195,160
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score 0 · Answer 2 · answered Sep 21 '16 at 08:33

0

table(factor(x, unique(union(x,y))))

table(factor(y, unique(union(x,y))))

answered Sep 21 '16 at 08:33

NRLP

568
3
16

How to count entries with specific values in R

2 Answers2