Bruce Durling introduces himself and his work helping various Clojure and technology communities in London. He explains how the Clojure library Incanter can be used for data science and provides examples of importing and manipulating data and creating plots. Durling also discusses future plans for Incanter and invites attendees to contribute to its development at monthly sprints.

1. Practical Magic - Clojure for
Data Scientists
Hi!
Iʼm Bruce Durling.
@otfrom on twitter.
Community
I help run the London Clojurians.
And help with the
• London Java Community
• London Python Dojo
• London Salesforce User Group.
Upcoming
• EuroClojure 24-25 May http://euroclojure.com Rich Hickey and
Stuart Halloway Keynotes
Work
Iʼm the CTO of Mastodon C.
Weʼre going to cut global CO2 by 1% by greenifying you hadoop
jobs in the cloud.

2. mastodonc.com mastodonc.blogspot.com @mastodonc
I already have
R/SPSS/PSSP/MatLab/Excel
• You can do most (all?) of it in clojure
• And you get prolog
• And you get hadoop w/Datalog (Cascalog)
• And you get Storm (realtime stats)
• And you get Web Apps
• And it is a free general purpose language
• Lots of developers love it
• But it is still beautiful and understandable
So, where should I start?
Incanter to the rescue
What is Incanter?
http://www.incanter.org http://data-sorcery.org/
http://github.com/liebke/incanter

3. Getting Started
project.clj
(defproject quiddswic “0.0.3”
description "Quick and Dirty Data Science with
Incanter and Clojure"
dependencies [[org.clojure/clojure "1.3.0"]
[incanter “1.3.0”
exclusions [swank-clojure
org.clojure/clojure org.clojure/clojure-contrib
org.clojars.bmabey/congomongo congomongo]] [clj-time “0.3.3”
exclusions [org.clojure/clojure
org.clojure/clojure-contrib]] [congomongo “0.1.7”
exclusions [org.clojure/clojure
org.clojure/clojure-contrib]]])
What is required?
(require ʻ[clj-time.format :as tformat]) (require ʻ[clj-time.core :as
time]) (require ʻ[clj-time.coerce :as coerce]) (require ʻ[incanter.core
:as incanter]) (require ʻ[incanter.stats :as stats]) (require
ʻ[incanter.charts :as charts]) (require ʻ[incanter.io :as io]) (use
ʻclojure.repl)
How do I get data in?
(def series (io/read-dataset “./beer.csv” :header true))

4. Strings are not dates
$map and date-clj conj-cols
(def dts (incanter/dataset [:dts] (incanter/$map (fn [d]
(tformat/parse (:year-month-day tformat/formatters) d)) [:date]
series)))
(def t (incanter/dataset [:millis] (incanter/$map (fn [d] (coerce/to-
long d)) [:dts] dts)))
(def s1 (incanter/conj-cols series dts t))
(incanter/head s1)
(incanter/view s1)
Now what do I do with it
How about a seasonal means?
(def dow (incanter/dataset [:dow] (incanter/$map (fn [d] (time/day-
of-week d)) [:dts] s1)))
(def s2 (incanter/conj-cols s1 dow))
(def sm (incanter/col-names (incanter/$rollup (fn [coll] (stats/mean
coll)) :beer :dow s2) [:season :mean]))
(def sm-ord (incanter/$order :season :asc sm))
(def s3 (incanter/$join [:season :dow] sm s2))
(incanter/head s3)

5. mean
(stats/mean (incanter/$ :beer s3))
sorting
(def sm-ord (incanter/$order :season :asc sm))
So, Iʼve got a lot of numbers
view
(incanter/view s1)
Plotting and Graphics
(def ts-plot (charts/time-series-plot (incanter/$ :seconds s1)
(incanter/$ :metric s1)))
(incanter/view ts-plot)
The Future
• Make it faster (mostly remove reflection)
• Integrate with frinj
• Big Data (hadoop, datomic)

6. Help us at our monthly sprints!
Join the london-clojurians google group to find out more.
Thanks!
Bruce Durling, @otfrom
CTO www.mastodonc.com @MastodonC
EuroClojure 24-25 May: http://euroclojure.com