I have the following code, READY, that my supervisor passed to me
fatores=c("Year","Month","DayofWeek","DayofMonth")
dadosFatores=apply(dados[,fatores],2,XXXX)
dados[,XXXX]=dadosFatores
In the exercise says that I should only change the XXXX to something that makes sense and return what the function asks, ie convert the variables into question into factors.
I tried to replace with as.factor , without much success.
Could someone help?
Changing my answer, there is actually a previous problem, you would have to use lapply instead of apply , because apparently apply will throw everything to an array and convert to character before returning for data.frame (had not tested the code before).
Generating a dummy data to illustrate:
dados <- data.frame(x = 1:10)
dados[, fatores] <- rep(c("a", "b", "c", "d"),10)
str(dados)
data.frame': 10 obs. of 5 variables:
$ x : int 1 2 3 4 5 6 7 8 9 10
$ Year : chr "a" "b" "c" "d" ...
$ Month : chr "c" "d" "a" "b" ...
$ DayofWeek : chr "a" "b" "c" "d" ...
$ DayofMonth: chr "c" "d" "a" "b" ...
With apply (does not work):
dados[,fatores]= apply(dados[,fatores], 2, as.factor)
str(dados)
'data.frame': 10 obs. of 5 variables:
$ x : int 1 2 3 4 5 6 7 8 9 10
$ Year : chr "a" "b" "c" "d" ...
$ Month : chr "c" "d" "a" "b" ...
$ DayofWeek : chr "a" "b" "c" "d" ...
$ DayofMonth: chr "c" "d" "a" "b" ...
With lapply (works):
dados[,fatores]= lapply(dados[,fatores], as.factor)
str(dados)
'data.frame': 10 obs. of 5 variables:
$ x : int 1 2 3 4 5 6 7 8 9 10
$ Year : Factor w/ 4 levels "a","b","c","d": 1 2 3 4 1 2 3 4 1 2
$ Month : Factor w/ 4 levels "a","b","c","d": 3 4 1 2 3 4 1 2 3 4
$ DayofWeek : Factor w/ 4 levels "a","b","c","d": 1 2 3 4 1 2 3 4 1 2
$ DayofMonth: Factor w/ 4 levels "a","b","c","d": 3 4 1 2 3 4 1 2 3 4
If an error appears in the code above, put the error message and a reproducible example so that we can understand what the problem is and the result of head(dados) and str(dados) in your question to see what the object is like >