[R] Data type in a data frame

[Rui Barradas]

Hello,

When read into a data.frame, R defaults to reading character strings as 
factors. If you don't want that, use option stringsAsFactors = FALSE. 
Using your dataset,


dat1 <- read.table(text = "
Observation   Gender  Dosage  Alertness
1             m       a               8
2             m       a              12
3             m       a              13
4             m       a              12
5             m       b               6
6             m       b               7
", header = TRUE)
str(dat2)

dat2 <- read.table(text = "
Observation   Gender  Dosage  Alertness
1             m       a               8
2             m       a              12
3             m       a              13
4             m       a              12
5             m       b               6
6             m       b               7
", header = TRUE, stringsAsFactors = FALSE)
str(dat2)


This is decided based on the setting of (which you can change)

options("stringsAsFactors")

Hope this helps,

Rui Barradas
Em 23-10-2012 15:43, asafwe escreveu:
> Hi all,
>
> How does R know to regard a variable as a factor and not a character?
> For example, consider the following table:
>
> Observation                Gender                Dosage
> Alertness
> 1                               m                        a
> 8
> 2                               m                        a
> 12
> 3                               m                        a
> 13
> 4                               m                        a
> 12
> 5                               m                        b
> 6
> 6                               m                        b
> 7
>
> When read into a dataframe, will "m", "a", "b" be regarded as a factor or as
> a character? How does R decide?
>
> Thanks a lot in advance,
>
> Asaf
>
>
>
> --
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