Lec01
Data manipulation with dplyr.
Announcements
- Handed out reading for Monday 9/19: A layered grammar of graphics by Wickham.
In-Class
- Slides: Tidy data, data manipulation verbs, and piping
%>%
. - In-class exercise:
- Code:
Lec01.R
- Code:
For the rest of the class, please download any Code or Data files listed above from GitHub as follows:
- Click on the GitHub link above
- Navigate to the corresponding lecture folder
- Click on the relevant file
- Click on the “Raw” button
- In your browser, go to File -> Save As… and save the file without
.txt
in the file name
Then please change the default application to open .R
files to RStudio. You
only need to do this once (unfortunately I don’t know how to do this on Windows):
- Navigate to
Lec01.R
in a Finder window - Right click the file and select Open With -> Get Info
- Under Open with: select RStudio and click Change All…
After-Class Updates
Connor pointed out an error with lines 134-136 in the original Lec01.R
file. The command add_rownames()
has been deprecated i.e. dropped. Replace these lines with the following, which uses the function rownames_to_column()
from the tibble
package:
mtcars <- mtcars %>%
tibble::rownames_to_column() %>%
rename("make_model"=rowname)
The ::
in tibble::
serves two functions:
- Sometimes two packages can have the same function name, like
filter()
exists in multiple packages. The::
disambiguates which package. - You can use a function from a package without loading the package itself using
library()
. So the above code block is identical in function to:
library(tibble)
mtcars <- mtcars %>%
rownames_to_column() %>%
rename("make_model"=rowname)