Reputation: 35
I'm trying to add a column to a dataframe and I'm using the rep() function. Why do the first line work, but the next one doesn't?
> S_Grime$Græsning=rep(1:2, 50:49)
> R_Grime$Græsning=rep(1:2, 34:27)
Error in rep(1:2, 34:27) : invalid 'times' argument
My data:
> head(S_Grime)
# A tibble: 6 x 3
Feltnummer value Græsning
<dbl> <dbl> <int>
1 1 6.26 1
2 2 5.72 1
3 3 8.74 1
4 4 5.33 1
5 5 6.23 1
6 6 8.67 1
> head(R_Grime)
# A tibble: 6 x 2
Feltnummer value
<dbl> <dbl>
1 2 2
2 3 2
3 4 2
4 5 2
5 7 2
6 11 2
> str(R_Grime)
tibble [61 x 2] (S3: tbl_df/tbl/data.frame)
$ Feltnummer: num [1:61] 2 3 4 5 7 11 12 13 14 15 ...
$ value : num [1:61] 2 2 2 2 2 2 2 2 4 2 ...
> str(S_Grime)
tibble [99 x 3] (S3: tbl_df/tbl/data.frame)
$ Feltnummer: num [1:99] 1 2 3 4 5 6 7 8 9 10 ...
$ value : num [1:99] 6.26 5.72 8.74 5.33 6.23 ...
$ Græsning : int [1:99] 1 1 1 1 1 1 1 1 1 1 ...
Upvotes: 2
Views: 2220
Reputation: 7941
From ?rep.int
:
If
times
consists of a single integer, the result consists of the whole input repeated this many times. Iftimes
is a vector of the same length as x (after replication by each), the result consists ofx[1]
repeatedtimes[1]
times,x[2]
repeatedtimes[2]
times and so on
The behaviour if times
is neither 1 nor the length of x is undefined.
If you're expecting 34 1s, followed by 27 2s, you should do rep(1:2, c(34,27))
. If you're expecting 1:2
to be recycled to the same length as 34:27
you'd need to specify that specifically with something like rep(rep(1:2, length.out=length(34:27)), 34:27)
Upvotes: 1