# Articles

## Contents

## General Articles

A Note on Programming Style Roger K.W. Hui & Kenneth E. Iverson

File:Aplj.pdf (pdf) Chris Burke

Array Processing with J (pdf) Milan Ondrus

Data Rummaging with J Joey Tuttle

File:Jacobs.pdf (pdf) Jan Jacobs (Computing & Control Engineering Journal December 2002)

Elegant Programming: #~ 1: = #@q: Chris Burke

Elegant Programming: &. dfh Chris Burke

Extended Integers in J Roger K.W. Hui

J for the APL Programmer Chris Burke and Roger K. W. Hui (updated version in wiki)

JGMM, Mixture Model in J for Density Estimation and Classification Pierre-Edouard Portier

J Team wins Judge's Prize in the ICFP'98 Functional Programming Contest Roger K.W. Hui

J4 and OOP Chris Burke

Little JOBS and Big JOBS John D. Baker

Memory Mapped Files in J Chris Burke

Notation as a Tool of Thought Kenneth E. Iverson (1979 Turing Award Lecture)

Rank and Uniformity Roger K.W. Hui

Seven Great Blunders of the Computing World Neville Holmes

Sparse Arrays in J Roger K.W. Hui

Using J with OLE2 Building Configuration Software for SAP AG Duncan Pearson & Adrian Smith

Zero Divided by Zero Eugene McDonnell

## At Play With J

The following articles by Eugene McDonnell are from his series “At Play With J” in *Vector*. They are also available as a book from
Lulu and Amazon.

- How the Roll Function Works V8#3
- MIMD Machines V10#2
- Prime Factorisation V10#3
- The 10,000,000,000th prime number V10#4
- Control structures V11#1
- Jacobi's Method V11#3
- Cribbage 15s V11#4
- Representations of a Permutation V12#1
- The Bauer-Mengelberg Problem V12#2
- Heron's Rule & Integer-Area Triangles V12#3
- Year's Digits for 1996 V12#4
- Riding a Unicycle V13#1
- Volutes V13#2
- Extended Integers V13#3
- Stumping the Rocket Scientist V13#4
- Oh, No, Not Eigenvalues Again! V14#1
- A Newer Random Link Generator V14#4
- To Summarise V15#1
- Maximum Infix Sums V15#2
- Crosswords and Life V15#3
- New Model Computer V15#4
- New Big Deal V16#1
- We'll Cross That Bridge When We Come To It V16#3
- An Open And Shut Case V16#4
- Blists in OLEIS V17#1
- Someone Just Moved! Who Was It? V17#2
- Four Cubes Redux V17#3
- Erdos Numbers & Pierce & Engel Expansions V17#4
- Boggle V18#1
- The Counterfeit Coin Problem V18#3
- Second-order Josephus V18#4
- J Be Nimble, J Be Quick V19#1
- Beware Scholes! V19#3
- Pick A Card, Any Card V19#4
- Greed V20#1
- The Magical Matrix V20#2
- Giddyap V20#3
- Jacob's Ladder V20#4
- The Google Test V21#1
- Metlov's Triumph V21#4
- Belgian Numbers V22#1
- Token Counting: APL versus J V22#3

## Vector Articles

The following are some articles on-line at *Vector*.

### General Interest

J Solution to Enigma 685 Dave Ziemann V10#2

A Note on the Easter Algorithm in J Keith Smillie V10#3

Fast Fourier Transforms, Diffraction Patterns, and J Ned W. Allis, Jeffrey P. Dumont, Flynn J. Heiss, Clifford A. Reiter V16#3

Hyperbolic Symmetry is a Breeze Cliff Reiter V17#3

Working with Existing Ascii Files Using J Memory Mapping Donald B. Pittenger V17#3

Web Image Galleries Made Routine Clifford Reiter V18#1

The Image2 Addon Clifford A. Reiter and Zachary X. Reiter V18#3

Review of “J: the Natural Language for Analytic Computing” Cliff Reiter V18#3

Inner Product Fractals from Fuzzy Logics Angela Coxe V19#2

Boolean Hexagonal Automata Angela Coxe and Cliff Reiter V19#3

Taming Barrel and Tilt Distortion Cliff Reiter V20#1

Solving the “Now I Know” Problem in J Howard A. Peelle V20#2

Using J in Excel Richard Hill V21#1

Celtic Knotwork in J Michael Horton V21#1

Time(r) for the Game of Life Cliff Reiter V21#3

CRCOMPARE in J Adam Dunne V21#4

Thoughts on the URN Problem E.A. Clough V21#4

A Sudoku Solver Roger Hui V21#4

Integer Apollonian Circle Packings in J Cliff Reiter V22#4

APL - a Glimpse of Heaven Bernard Legrand V23#1

3-D Cellular Automata and the Game of Life Timothy K. Zirkel V23#3

Tacit J and I Neville Holmes V23#3

GPS and J Propel an Adirondack Hiking Guide Cliff Reiter V23#3

A J Simulator for a Meccano Differential Analyzer Keith Smillie V23#3

Partitions of numbers: an efficient algorithm in J R.E. Boss V23#4

Cauchy Curves William R. Jones & Cliff Reiter V24#1

Quick calculation of Kendall’s Rank Correlation Distribution Gordon Sutcliffe V24#1

Generating combinations in J efficiently R.E. Boss V24#2&3

In Session: On average Roger Hui V24#2&3

A commentary on the formulator Neville Holmes V24#4

Simulating the Enigma Keith Smillie V24#4

Odd-order magic squares expressed in J John C. McInturff V25#1

What is it about infinity? Sylvia Camacho & Graham Parkhouse V25#1

Bicubic Interpolation in J Cliff Reiter V25#3

What is it about infinity? Norman Thomson V25#3

Savitzky-Golay interpolation for smoothing values and derivatives David Porter and Cliff Reiter V25#4

Fibonacci and golden spirals Cliff Reiter V26#1

L-systems in J R.E. Boss V26#1

All integer partitions: J programs compared Howard A. Peelle V26#2

Squares, neighbours, probability, and J John C. McInturff V26#2

Using J for Actuarial Applications Part 1: The Chain-Ladder Method Jeremy Smith V26#4

Larger than life automata Cliff Reiter in press

### Backgammon Tools

*Section 2 is currently unavailable*

Backgammon tools in J: 1. Bearoff expected rolls Howard A. Peelle V24#2&3

Backgammon Tools in J: 2. Wastage Howard A. Peelle V24#4

Backgammon Tools in J: 3. Two-sided bearoff probabilities Howard A. Peelle V25#4

Backgammon Tools in J: 4. Ace-point bearoffs Howard A. Peelle V26#4

### Vector Series - Functional Calculation

Functional calculation 0: Numerical Aperitif Neville Holme V23#3

Functional calculation 1: Numerical Ingredients Neville Holme V23#4

Functional calculation 2: The year 1997 Neville Holmes V24#1

Functional calculation 3: Structural Ingredients Neville Holmes V24#2&3

Functional calculation 4: The year 1998 Neville Holme V23#4

Functional Calculation 5: Operations Neville Holmes V25#1

### J-ottings

This is a series of articles by Norman Thomson, see Articles/J-ottings.

## Journal of J

ISSN:2174-9280

An interdisciplinary journal on the J programming language and its applications in science.