Database Reference
In-Depth Information
How it works…
Similar to all Lisp's (List Processing), Clojure is usually read from the inside out and from
right to left. Let's break it down.
clojure.java.io/reader
opens the ile for reading.
read-all-json
parses all of the JSON documents in the ile into a sequence. In this case, it
returns a vector of the maps.
incanter.core/to-dataset
takes a sequence of maps and
returns an Incanter dataset. This dataset will use the keys in the maps as column names, and
it will convert the data values into a matrix. Actually,
to-dataset
can accept many different
data structures. Try
doc to-dataset
in the REPL (
doc
shows the documentation string
attached to the function), or see the Incanter documentation at
http://data-sorcery.
org/contents/
for more information.
Reading data from Excel with Incanter
We've seen how Incanter makes a lot of common data-processing tasks very simple, and
reading an Excel spreadsheet is another example of this.
Getting ready
First, make sure that your Leiningen
project.clj
ile contains the right dependencies:
(defproject getting-data "0.1.0-SNAPSHOT"
:dependencies [[org.clojure/clojure "1.6.0"]
[incanter "1.5.5"]"]])
Also, make sure that you've loaded those packages into the REPL or script:
(use 'incanter.core
'incanter.excel)
Find the Excel spreadsheet you want to work on. The ile name of my spreadsheet is
data/
small-sample-header.xls
, as shown in the following screenshot. You can download this
