Often we need to cut down the data to make it more useful. One common transformation is to pull out all the values from one or more columns into a new dataset. This can be useful for generating summary statistics or aggregating the values of some columns.
The Incanter macro $
slices out parts of a dataset. In this
recipe, we'll see this in action.
For this recipe, we'll need to have Incanter listed in our project.clj
file:
:dependencies [[org.clojure/clojure "1.4.0"] [incanter "1.4.1"]]
We'll also need to include incanter.core
and incanter.io
in our script or REPL.
(use '(incanter core io))
We'll also need some data. This time we'll use the race data from the US census data available at http://censusdata.ire.org/. However, instead of using the data for one state we'll use all states' data. These have to be downloaded separately and joined together. I've already done this, and the file is available for download at http://www.ericrochester.com...