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I have two vectors that one (v.num) corresponds to one variable in df and the other one (v.type) is a vector that I want to fill into the df with the corresponding vector.

 v.num<-c(5, 6, 7, 8, 9, 10, 11)
 v.type<-c(1, 3, 5, 2, 2, 4, 1)

The df looks like this:

set.seed(2016)
df <- data.frame(v.num=sample(5:11, 40000, replace=TRUE), obs=rnorm(40000))

What I want to do is create a v.type vector and store the v.type that corresponds to v.num

Like:

head(df)
     v.num    obs    v.type
 1     6  1.6149522    3
 2     6 -0.2676644    3
 3    10  0.3013365    4
 4     5 -0.8514377    1
 5     8  0.5786278    2
 6     5 -1.2974004    1

I tried

for(i in 1:nrow(df)){
    for(v in 1:length(v.num){
    if(v.num[v]==df$v.num[i]){df$v.type[i]<-v.type[v]}
  }}

But it takes pretty long, because I have 40000 rows. What is the most efficient way to do this task?

user3077008
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1 Answers1

3

Check out the following code:

v.num<-c(5, 6, 7, 8, 9, 10, 11)
v.type<-c(1, 3, 5, 2, 2, 4, 1)
set.seed(2016)
df <- data.frame(v.num=sample(5:11, 40000, replace=TRUE), obs=rnorm(40000))


df$v.type <- v.type[match(df$v.num, v.num)]
Raad
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