Profile

Cover photo
John Cook
Works at Singular Value Consulting
Attended University of Texas at Austin
Lives in Houston, TX
28,831 followers|6,569,294 views
AboutPostsPhotos

Stream

John Cook

Shared publicly  - 
 
Visualizing Zwicker's method of combining loudness, sharpness, roughness and fluctuation strength into a single annoyance metric
1
1
Add a comment...

John Cook

Shared publicly  - 
16
2
David L. Craig's profile photoCarlos Eduardo Olivieri's profile photo
2 comments
 
Great!
Add a comment...

John Cook

Shared publicly  - 
 
Praise for functional programming. From https://youtu.be/hzf3hTUKk8U
9
1
Jan Moren's profile photoMatthew Calef's profile photo
2 comments
 
FP makes me happy, but there was that one time I wanted to add a print statement and I either had to change a zillion function signatures or use utilities whose names made me feel bad about myself.
Add a comment...

John Cook

Shared publicly  - 
 
There are basically four types of integral equations: Volterra and Fredhom, each of the first and second kind. Here's a chart to keep them straight.
1
Add a comment...

John Cook

Shared publicly  - 
 
The Mittag-Leffler function generalizes the exponential function. Probability distributions based on the exponential function (exponential, Poisson) have Mittag-Leffler generalizations.

Just as the exponential function satisfies the differential equation y' = ay, the Mittag-Leffler function satisfies the analogous fractional differential equation.
The Mittag-Leffler function is a generalization of the exponential function. It leads to generalizations of the exponential and Poisson distributions.
6
1
Add a comment...

John Cook

Shared publicly  - 
 
I heard someone say the other day that the advantage of formal software validation methods is that they let you explore the corners, cases where intuition
7
2
Add a comment...
Have him in circles
28,831 people
edwin samayoa's profile photo
Annie Shan's profile photo
Jeremy Carpenter's profile photo
Brandon Velasquez's profile photo
Kerry Zhang's profile photo
Stephen Ralston's profile photo
pamela carter's profile photo
Gino Tagaytay's profile photo
Charles Jackson's profile photo

John Cook

Shared publicly  - 
 
There are two units of loudness in common use: phon and sone. The relation between them is complicate by a change in perceived sound intensity that happens around 40 dB. This page explains what the two units are, how to convert between them, and gives an online calculator for going from one to the other.

http://www.johndcook.com/phon_sone.html
1
Add a comment...

John Cook

Shared publicly  - 
 
"The idea that science demystifies the world, I just don't understand that. I feel that the deeper down the scientific rabbit hole I go, the bigger and grander and more magical the world seems." -- Stanford Gibson
As powerful as mathematical modeling can be, some things are most economical to study with analog models. These analog models still involve some math modeling.
10
1
Robert Rambusch's profile photo
Add a comment...

John Cook

Shared publicly  - 
 
You can take the first derivative, second derivative, etc. of a function. What would it mean to take the 1.7th derivative or the πth derivative?

There are several ways to do this. The simplest approach, in my opinion, relies on Fourier transforms. This blog post looks at a more direct approach. It's more elementary but also a little more complicated.
You can define a fractional derivative by defining fractional powers of the backward difference operator via the generalized binomial theorem.
10
1
Anil Das's profile photoJohn Cook's profile photo
2 comments
 
+Anil Das Yes
 ·  Translate
Add a comment...

John Cook

General Discussion  - 
 
The stereotypical Lisp programmer is arrogant, but that may be based on a tiny biased sample of people who write about Lisp.
4
Chattrawit S.'s profile photo
 
Could you please tell us a little bit which industry use this programming language? 
Add a comment...

John Cook

Shared publicly  - 
 
Acoustic roughness is measured in aspers. Here's the reference value for 1 asper.
7
Add a comment...

John Cook

Shared publicly  - 
 
A series of papers by +Brian Beckman on Kalman filtering and functional folds
A few weeks ago I started a series of posts on various things you could do with a functional fold. In the first post I mentioned that the idea came from a
5
Bill Igoe's profile photo
 
Xool. Bookmark ed.
Add a comment...
People
Have him in circles
28,831 people
edwin samayoa's profile photo
Annie Shan's profile photo
Jeremy Carpenter's profile photo
Brandon Velasquez's profile photo
Kerry Zhang's profile photo
Stephen Ralston's profile photo
pamela carter's profile photo
Gino Tagaytay's profile photo
Charles Jackson's profile photo
Work
Occupation
Applied mathematician
Skills
Mathematical modeling, Bayesian statistics, software design, writing clear prose
Employment
  • Singular Value Consulting
    Owner, 2013 - present
    I've consulted for some of the world's largest software and biotech companies, as well as for law firms and smaller companies.
  • M. D. Anderson Cancer Center
    Research Statistician, 2000 - 2013
    Bayesian statistics, clinical trial design, simulation, software project management
  • NanoSoft
    Senior consultant
    Desktop, web, and mobile software development
  • Western Atlas
    Software developer
    Desktop software development, digital signal processing
  • Vanderbilt University
    Assistant professor
    Research in nonlinear partial differential equations and modelling
Places
Map of the places this user has livedMap of the places this user has livedMap of the places this user has lived
Currently
Houston, TX
Previously
Texarkana, TX - Nashville, TN - Austin, TX - Washington, DC
Contact Information
Work
Phone
(832) 422-8646
Story
Tagline
Connector
Introduction
I solve problems by making connections.

I work as a consultant, bringing together the experience I gained from my previous careers as a math professor, programmer, manager, and statistician. I enjoy combining ideas to solve problems and see the solutions carried out.

You can find out more about my work here.
Education
  • University of Texas at Austin
    Ph. D. in Mathematics
Basic Information
Gender
Male