Machine Learning
Made Easy with Perl
Lino Ramirez
ramirez@aranducorp.com

From Wikipedia

From Wikipedia

From Wikipedia

From Wikipedia
From Wikipedia

From Wikipedia
From Wikipedia

From Wikipedia

$$$

8 years later ...

A MSc later ...

A PhD later ...

Computers
should “empower”
people
not replace them

Key Lesson:
“It's all about
empowering people”

What do you want to
accomplish?
Machine Learning: 3 phases

Well ... There is this guy ...
Machine Learning: 3 phases

Video

Is that helping?
Video

Not really! You should ...
Video

Machine Learning:

Machine Learning: 3 phases
Preparation
Phase
Modeling Implementation
Phase Phase

Machine Learning: Preparation
•Definition
•Gathering
•Analysis
Preparation •Cleaning
Phase •Selection
Modeling Implementation
Phase Phase

Machine Learning: Modeling
•Selection
Preparation
•Development
•Evaluation Phase
Modeling Implementation
Phase Phase

Machine Learning:
Implementation
•Evaluation
•Implementation
Preparation
Phase
Modeling Implementation
Phase Phase

Case Study

Case Study
Implemented 100% in
Perl

Problem
For a selected group of components
for Nasdaq composite, if I cluster
the financial quotes into three
segments, what are their profiles?

Preparation Phase

Components for Nasdaq composite?

Cluster?

Profiles?

Gathering data

Analysis

Analysis
Missing values

Analysis
Missing values
Ask customer

Analysis
Different range of values

Analysis
Different range of values
Scaling

Modeling Phase

Selection

Clustering
Method for dividing data elements into
groups so that items in the same group
are as similar as possible, and items in
different groups are as dissimilar as
possible.

Fuzzy C-Means (FCM)
Items are allowed to belong to more
than one group

Membership to Cluster Centered in (5.80, 5.65 )
9.5
0.09
9
8.5
0.11 0.01
8
7.5
0.52 0.13
7
6.5
0.98 0.98 0.39
6
5.5
0.94 0.96
5
4.5
4.5 5.5 6.5 7.5 8.5 9.5

Membership to Cluster Centered in (5.80, 5.65 )
9.5
0.09
9
8.5
0.11 0.01
8
7.5
0.52 0.13
7
6.5
0.98 0.98 0.39
6
5.5
0.94 0.96
5
4.5
4.5 5 5.5 6 6.5 7 7.5 8 8.5 9 9.5

Clusters' Shape
Euclidean distance
Manhattan distance
Tchebychev distance

FCM: Step by Step
Initialize partition matrix
stop = false
While ( stop is false )
Compute clusters' centers
Compute new partition matrix
If partition matrices are close to each other
stop = true
Else
partition matrix = new partition matrix

Development

Installing PDL
Ubuntu or Debian based distribution
$ sudo apt-get install pdl pgplot5
$ sudo apt-get install libterm-readline-gnu-perl
$ sudo cpan
cpan> install PGPLOT

Installing PDL (cont.)
Other Linux distribution or Mac OS X:
See:
http://wiki.jach.hawaii.edu/pdl_wiki-bin/wiki/SiteMap
Go to:
Getting Started with PDL
and then to:
Installing PDL the quick and easy way

Getting Started with PDL
Project Homepage:
http://pdl.perl.org/
Mailing Lists:
http://pdl.perl.org/maillists/index_en.html
PDL at PerlMonks:
http://perlmonks.org/?node_id=626721

n−1
m
uij xj
∑
j=0
vi = , 0≤i≤c−1
n−1
m
uij
∑
j=0

1
u ij= c −1
2 / m −1 
∑  d ij /d kj 
k =0

Evaluation

Implementation Phase

Implementation Phase
Ask your customer

Case Study

Case Study
Implemented partially
in Perl

Problem
For patients with scoliosis,
Can you design a system that using
surface topography could predict
internal spinal deformity sufficiently
well to replace some radiographs?

Preparation Phase

Scoliosis?

Scoliosis

Surface Topography?

Predict?

Gathering data

Analysis

Additional features?

Analysis
Missing values

Analysis
Missing values
Ask customer

Analysis
Different range of values

Analysis
Different range of values
Scaling

Modeling Phase

Selection

SVM vs. Neural Networks

Neural Networks Classifier

Neural Networks Classifier

Neural Networks Classifier

Neural Networks Classifier

Neural Networks Classifier

Support Vector Machines Classifier

Support Vector Machines Classifier

Development

LIBSVM -- A Library for Support
Vector Machines
http://www.csie.ntu.edu.tw/~cjlin/libsvm/
Award winning SVM package distributed
with a “modified BSD license”

Development
SVM configuration

Development
SVM configuration
Crossvalidation

Evaluation

Evaluation
How to test the performance?

Evaluation
How to test the performance?
Leave one out

Evaluation
Results

Evaluation
Results
85% determining
need of treatment

Evaluation
Results
69% 3-class classification

Implementation Phase

Implementation Phase
Ask your customer

Conclusion

Conclusion
Perl excels at empowering
people in all three phases of
the development of a
machine learning application

Thank you!
Open for questions now or later
for samples and slides email me at:
ramirez@aranducorp.com
This work is licensed under a Creative Commons
Attribution-NonCommercial-ShareAlike 2.5 License

Linear Polynomial
RBF Sigmoid