Basic Data Verbs

Three kinds of verbs for data wrangling

1. Data verbs
2. Reduction verbs
3. Transformation verbs

Non-wrangling verbs

There will also be verbs for graphics, loading data, etc., but for wrangling we’ll need mainly these three types. Examples:

• library() – attaches the software distributed in a package to your session of R
• read.csv() and other file-reading functions. Creates a data table given the location of a file containing those data.
• scatterGraphHelper() – takes a data table as input, but produces graphics as output.
• data() – accesses data from a package. data() is not a data verb!

Data Verbs

What distinquishes a data verb from a reduction or transformation verb?

• Data verbs create a new data table, from an input data table.

Some commonly used data verbs.

1. summarise()
2. group_by()
3. filter()
4. mutate()
5. select()
6. arrange()
7. join (there’s a family of joins – more on this later)

Reduction verbs

Characteristics?

Variable in, a single number out.

Examples?

Transformation verbs

Variable in, variable out.

Examples?