Displaying 5 results from an estimated 5 matches for "27_cat".
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2018 May 11
3
add one variable to a data frame
Hi All,
I have a data frame dat1:
dat1 <-data.frame(N=seq(1, 12,1), B=c("29_log","29_log", "29_log", "27_cat", "27_cat",
"1_log", "1_log", "1_log", "1_log", "1_log",
"3_cat", "3_cat&quo...
2018 May 11
0
add one variable to a data frame
...e way to approach it, using the coercion of factor to numeric.
Note that I changed your data.frame() statement to avoid coercing
strings to factors, just to make it simpler to set the levels.
dat1 <-data.frame(N=seq(1, 12,1), B=c("29_log","29_log", "29_log",
"27_cat", "27_cat", "1_log", "1_log", "1_log", "1_log", "1_log",
"3_cat", "3_cat"), stringsAsFactors=FALSE)
dat1$C1 <- as.numeric(factor(dat1$B, levels=unique(dat1$B)))
And here's a way using rle()
dat1$C2 <-...
2018 May 11
3
add one variable to a data frame
...e way to approach it, using the coercion of factor to numeric.
Note that I changed your data.frame() statement to avoid coercing strings to factors, just to make it simpler to set the levels.
dat1 <-data.frame(N=seq(1, 12,1), B=c("29_log","29_log", "29_log", "27_cat", "27_cat", "1_log", "1_log", "1_log", "1_log", "1_log", "3_cat", "3_cat"), stringsAsFactors=FALSE)
dat1$C1 <- as.numeric(factor(dat1$B, levels=unique(dat1$B)))
And here's a way using rle()
dat1$C2 <-...
2018 May 11
2
add one variable to a data frame
...it depends completely on the data beig
grouped in order as the OP showed. It will fail if this is not the case.
If, for example, the data appeared as:
> set.seed(1234)
> ix <- sample(1:12)
> dat1[ix,]
N B
2 2 29_log
7 7 1_log
11 11 3_cat
6 6 1_log
10 10 1_log
5 5 27_cat
1 1 29_log
12 12 3_cat
3 3 29_log
8 8 1_log
4 4 27_cat
9 9 1_log
then Don's solution will still work. The above doesn't.
So this emphasizes the importance of precisely and completely specifying
the nature of your data. Hence: which is it? -- all the groups appearing
together...
2018 May 11
0
add one variable to a data frame
Sarah's solutions are good, and here's another, even more basic:
tmp1 <- unique(dat1$B)
tmp2 <- seq_along(tmp1)
dat1$C <- tmp2[ match( dat1$B, tmp1) ]
> dat1
N B C
1 1 29_log 1
2 2 29_log 1
3 3 29_log 1
4 4 27_cat 2
5 5 27_cat 2
6 6 1_log 3
7 7 1_log 3
8 8 1_log 3
9 9 1_log 3
10 10 1_log 3
11 11 3_cat 4
12 12 3_cat 4
As a single line command:
dat1$C <- seq(length(unique(dat1$B)))[ match( dat1$B, unique(dat1$B) )]
-Don
--
Don MacQueen
Lawrence Livermore National Laboratory
7000 East Ave...