As the Second Edition of Getting Started with R was going to press, Rstudio changed the function it uses to import data in the Import Dataset tool, from the base function read.csv() to the read_csv() function in the readr package. Since then, the Import Dataset button gives a menu with an option to use either (“base” uses read.csv and “readr” uses read_csv) From the Rstudio Blog about the readr package:
Compared to base equivalents like read.csv, readr is much faster and gives more convenient output: it never converts strings to factors, can parse date/times, and it doesn’t munge the column names.
Great! If you have dates and times in a column, its possible that read_csv will see this and then correctly format them as dates. So you wouldn’t need to do this yourself (covered in Appendix of Chapter 2 of the Second Edition).
Something else you might notice is that the data appears different if you look at it in the Console. This is because read_csv brings the data in as a special type of object called a tibble. (The standard read.csv function bring the data in as a standard data.frame.) You can read all about tibbles on the RStudio blog. Why are they better than data.frames? First, they only show the first ten lines and as many variables as will comfortably fit when you look at them in the Console, and the type of variable is given, and the number of additional rows and variables not displayed. E.g.:
library(readr)
dd <- read_csv(readr_example("mtcars.csv"))
## Parsed with column specification:
## cols(
## mpg = col_double(),
## cyl = col_double(),
## disp = col_double(),
## hp = col_double(),
## drat = col_double(),
## wt = col_double(),
## qsec = col_double(),
## vs = col_double(),
## am = col_double(),
## gear = col_double(),
## carb = col_double()
## )
dd
## # A tibble: 32 x 11
## mpg cyl disp hp drat wt qsec vs am gear carb
## <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
## 1 21 6 160 110 3.9 2.62 16.5 0 1 4 4
## 2 21 6 160 110 3.9 2.88 17.0 0 1 4 4
## 3 22.8 4 108 93 3.85 2.32 18.6 1 1 4 1
## 4 21.4 6 258 110 3.08 3.22 19.4 1 0 3 1
## 5 18.7 8 360 175 3.15 3.44 17.0 0 0 3 2
## 6 18.1 6 225 105 2.76 3.46 20.2 1 0 3 1
## 7 14.3 8 360 245 3.21 3.57 15.8 0 0 3 4
## 8 24.4 4 147. 62 3.69 3.19 20 1 0 4 2
## 9 22.8 4 141. 95 3.92 3.15 22.9 1 0 4 2
## 10 19.2 6 168. 123 3.92 3.44 18.3 1 0 4 4
## # … with 22 more rows
In summary, everything in the Second Edition will work just fine, but what you see in the Console might look a little different at times.
