Ajay Ohri - Python for R Users: A Data Science Approach

1. Chapter 03

1. Chapter 01
2. Chapter 02
3. Chapter 04
4. Chapter 05
5. Chapter 06

Ajay Ohri

This edition first published 2018
2018 John Wiley & Sons, Inc.

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Library of Congress CataloguinginPublication Data

Name: Ohri, A. (Ajay), author.
Title: Python for R users : a data science approach / Ajay Ohri.
Description: Hoboken, NJ : John Wiley & Sons, 2018. | Includes bibliographical references and index. | Identifiers: LCCN 2017022045 (print) | LCCN 2017036415 (ebook) | ISBN 9781119126775 (pdf) | ISBN 9781119126782 (epub) | ISBN 9781119126768 (pbk.)
Subjects: LCSH: Python (Computer program language) | R (Computer program language)
Classification: LCC QA76.73.P98 (ebook) | LCC QA76.73.P98 O37 2017 (print) | DDC 005.13/3dc23
LC record available at https://lccn.loc.gov/2017022045

Cover design: Wiley
Cover images: (Background) Duncan Walker/iStockphoto

Dedicated to my family in Delhi, Mumbai, and the United States

and

Kush Ohri (my son whom I love very much)

and

Jesus Christ (my personal savior)

I started my career with selling cars in 2003. That was my first job after 2 years of MBA and 4 years of engineering. In addition, I took off 2 years to enter a military academy as an officer cadet (dropped out in 1 year) and as a physicist (dropped out after 1 year). Much later, I dropped out of my PhD Track (MS Stats) after 1 year in Knoxville. I did not do very well in statistics theory in my engineering, my MBA, or even my grad school. I was only interested in statistical software and fortunately I was not very bad at using it. So in 2004, I dropped out of selling cars and entered into writing statistical software for General Electrics then Indiabased offshore company.

I used a language called SAS for a software called Base SAS. The help provided by the software company called SAS for this software and language was quite nice, so it was nice to play with data and code all day and be paid to have fun. After a few years of job changes, I came across opensource software when I started building my own startup. I really like SAS as a language and a company, but as a startup guy I could not afford it, and the SAS University Edition was not there in 2007. Since I needed money to pay for diapers of my baby Kush, and analysis was the only gift God had given me, I turned to R.

R, Open Office, and Ubuntu Linux were my first introduction to opensource statistical computing, and I persevered in it. In 2007 I started my own startup in business analytics writing and consulting, Decisionstats.com. In 2009 I entered the University of Tennessee for a funded assistantship, I interned in Silicon Valley for a few weeks in the winter, and I dropped out on medical reasons after taking courses across multiple departments from graphics design and genetic algorithms from Computer Science Department, apart from Statistics Department. Crossdomain training helped me a lot to think in various ways to give simple solutions, and I will always be thankful to the kind folks in Statistics and Computer Science Department of the University of Tennessee.

Once I mastered my brain around the vagaries of troubleshooting in Linux and of objectoriented programming on R, I was good to go to give consulting projects for data analysis. Those days we used to call it business analytics, but today of course we call it data science.

Since I often forget things including where I kept my code, I started blogging on things that I felt were useful and might be useful to others. After a few years I discovered that in the real world it was not what I knew, but who I knew that really helped my career. So I began interviewing people in Analytics and R and my blog viewership took off. My blog philosophy continues to bea blog post should be useful, it should be unique, and it should be interesting. In 2016, I had amassed 1,000,000 views on DecisionStats.comagain a surprising turn of events for me. I am most grateful to the 100 plus people who agreed to be interviewed by me.

2007 and 2008 were early days for analytics blogging for sure. After a few years I had enough material to put together a book and enough credibility to publish with a publisher. In 2012 I came up with my first book and in 2014 I came up with my second book. In 2016, the Chinese translation of my first book was realized. Surprisingly for me, a review of my second book appeared in the Journal of Statistical Software.

After publishing two books on R, mentoring many startups by consulting and training, engaging consulting clients in realworld problems, and making an established name in social media, I still felt I needed to learn more.