Reader small image

You're reading from  Clojure for Data Science

Product typeBook
Published inSep 2015
Reading LevelIntermediate
Publisher
ISBN-139781784397180
Edition1st Edition
Languages
Right arrow
Author (1)
Henry Garner
Henry Garner
author image
Henry Garner

Henry Garner is a graduate from the University of Oxford and an experienced developer, CTO, and coach. He started his technical career at Britain's largest telecoms provider, BT, working with a traditional data warehouse infrastructure. As a part of a small team for 3 years, he built sophisticated data models to derive insight from raw data and use web applications to present the results. These applications were used internally by senior executives and operatives to track both business and systems performance. He then went on to co-found Likely, a social media analytics start-up. As the CTO, he set the technical direction, leading to the introduction of an event-based append-only data pipeline modeled after the Lambda architecture. He adopted Clojure in 2011 and led a hybrid team of programmers and data scientists, building content recommendation engines based on collaborative filtering and clustering techniques. He developed a syllabus and copresented a series of evening classes from Likely's offices for professional developers who wanted to learn Clojure. Henry now works with growing businesses, consulting in both a development and technical leadership capacity. He presents regularly at seminars and Clojure meetups in and around London.
Read more about Henry Garner

Right arrow

The log-normal distribution


The log-normal distribution is simply the distribution of a set of values whose logarithm is normally distributed. The base of the logarithm can be any positive number except for one. Like the normal distribution, the log-normal distribution is important in the description of many naturally occurring phenomena.

A logarithm represents the power to which a fixed number (the base) must be raised to produce a given number. By plotting the logarithms as a histogram, we've shown that these powers are approximately normally distributed. Logarithms are usually taken to base 10 or base e: the transcendental number that's equal to approximately 2.718. Incanter's log function and its inverse exp both use base e. loge is also called the natural logarithm or ln, because of the properties that make it particularly suitable in calculus.

The log-normal distribution tends to occur in processes of growth where the growth rate is independent of size. This is known as Gibrat's law...

lock icon
The rest of the page is locked
Previous PageNext Page
You have been reading a chapter from
Clojure for Data Science
Published in: Sep 2015Publisher: ISBN-13: 9781784397180

Author (1)

author image
Henry Garner

Henry Garner is a graduate from the University of Oxford and an experienced developer, CTO, and coach. He started his technical career at Britain's largest telecoms provider, BT, working with a traditional data warehouse infrastructure. As a part of a small team for 3 years, he built sophisticated data models to derive insight from raw data and use web applications to present the results. These applications were used internally by senior executives and operatives to track both business and systems performance. He then went on to co-found Likely, a social media analytics start-up. As the CTO, he set the technical direction, leading to the introduction of an event-based append-only data pipeline modeled after the Lambda architecture. He adopted Clojure in 2011 and led a hybrid team of programmers and data scientists, building content recommendation engines based on collaborative filtering and clustering techniques. He developed a syllabus and copresented a series of evening classes from Likely's offices for professional developers who wanted to learn Clojure. Henry now works with growing businesses, consulting in both a development and technical leadership capacity. He presents regularly at seminars and Clojure meetups in and around London.
Read more about Henry Garner