A commentary on the formulator

Out now on Vector: Neville Holmes elaborates on his scheme for a commodity calculator

How the mathematicians won the war

Keith Smillie pits J and his wits against he famous cipher machine in Simulating the Enigma. Online now.

The Year 1998

Neville Holmes concludes his series “Functional calculation in J” with The Year 1998. Online now.

Wasted on the boards

Howard Peelle continues calculating his way through backgammon. New article.

Reference animations for J

Bob Therriault is in the process of developing some reference animations for J.

He writes on my blog:

We are hoping to create an easier conceptual access to some of J's array processing primitives. What we really would like is feedback from those with 'fresh eyes'. So if anyone has access to a classroom of learners discovering array processing languages, send them our way!

J Animations These are great, folks. Take a look.

At Play With J: 2nd edn.

The second edition of At Play With J, collected from Eugene McDonnell’s columns for Vector, has been published at Lulu.com.

Here in one volume are Eugene McDonnell’s 41 excellent articles published between 1993 and 2006. They form a series of straightforward but profound mathematical investigations which are not only entertaining but expand the mind.

The classical tradition founded by Fermat and Gauss mystifies the mathematical art by concealing the way in which the investigator found the solution in the first place. Trainee researchers will gain reassurance from the fact that the author does not shy away from expressing perplexity and puzzlement along the often rocky road to a solution. As such it constitutes a unique masterclass in how to do mathematical research.

The second edition has been produced by a team of J experts, revising and reworking the examples to correspond to best practice with J 6.02. With prefaces by Roger Hui and Chris Burke.

The first edition reproduced the original Vector articles with only minor amendments. But J evolved over the many years during which McDonnell wrote his column, and in the latest version of J not all the examples work as they were given. The first edition is of largely historical interest.

Grammar for pandas

In the latest J-ottings column, just posted to Vector, Norman Thomson mixes it with pandas, shoots and leaves. See Punctuation and rank

Combining far faster

In a new article posted at Vector, R.E. Boss harvests new insights from generating combinations faster in J.

Donald McIntyre

Roger Hui on the J Forum:

Donald B. McIntyre (1923-08-15 to 2009-10-21) passed away peacefully in the afternoon of October 21. Donald was an eminent geologist who pioneered the use of computers in geology. He was a gifted and inspiring teacher, an early and long-time APL and J user, and a friend and colleague of Ken Iverson and myself. He is survived by his wife Ann and his son Ewen. A memorial service will be held in St John’s Kirk in Perth, Scotland, this coming Friday, October 30.

Information about Donald’s life and times and his work can be found at www.mcintyre.me.uk

Professor McIntyre was a generous contributor to Vector. He is greatly missed.

Finnish Forest Seminar 15-16 Apr 2010

FinnAPL has announced its annual Foreset Seminar w3ill be held “somewhere in Southern Finland” on 15-16 April 2010. The programme should cover the versions of Dyalog, Windows and J and some databases.

Contact Kimmo Linna for details: kimmo.linna@finnair.com

Exploring the beauty of J

Luis Diego Fallas has been exploring J on his blog Exploring Beautiful Languages.

JobWatch: UK

Python Senior Software Developer Hedge Fund/Finance London

Python Senior Software Developer/Python Programmer is required for exciting and progressive Hedge Fund Financial company based in London. They are looking for an enthusiastic and experienced in Python and Unix/Linux Software Developer/Python Programmer. An interest in functional programming and its application in the real world would be useful. The role would suit developers with at least five years experience and proven ability to deliver working software. You might also have some of the following skills in C, Haskell, APL/J/K, Lisp, Django and significant part of childhood spent hacking away in 8-bit assembly language. Join an exciting company with many opportunities to progress your Python career. Send your CV for immediately review and further details.
Location London
Country UK
Rate £45k to £80k Per: annum + Benefits: Excellent Benefits
Employment Agency Oho Group Ltd
Contact Burim Hykaj
Telephone 0207 622 5155
Email Burim.Hykaj.1C2CB.3892E@mail.jobserve.com
Reference JS055
Posted Date 15/10/2009 18:30:48

Reposted from JobServe

Beyond average

The Dfn version of the classic APL expression for the average or arithmetic mean is widely thought to be unimprovable. Roger Hui shows it’s not.

JobWatch UK

Senior and graduate Python developers wanted with APL, J or K experience preferred:

Graduate Python Developers are required to work for a new emerging leader in the information security industry based in South West London.

You will be a part of a company that is growing rapidly in size and in reputation. As one of their Graduate Python developers you will be in a key position to be a part of something big and exciting, giving you endless opportunities to progress rapidly from a Graduate Python Developer to a Senior Python Developer position. You will receive an excellent starting salary, long holidays and discretional bonuses. You will ideally have had good academic experience working with Python and you will have a strong interest in Linux/Unix. You will have at least a 2:1 or above from a redbrick University and you will ideally have A's and B's at A-level.

A background in any of C, Haskell, APL/J/K, Lisp, Django would be beneficial but they are not essential.

Also…

Graduate Python Developers are required to work for a new emerging leader in the information security industry based in South West London. You will be a part of a company that is growing rapidly in size and in reputation. As one of their Graduate Python developers you will be in a key position to be a part of something big and exciting, giving you endless opportunities to progress rapidly from a Graduate Python Developer to a Senior Python Developer position. You will receive an excellent...

Contact Dan Seddon at Oho Group on +44 20 7622 6399.

Functional programming in J

In the third instalment of his series, Neville Holmes introduces us to the structural ingredients

At Play With J

The first edition of At Play With J, collected from Eugene McDonnell’s columns for Vector has been published at Lulu.com.

The first edition reproduces the original Vector articles with only minor amendments. But J has evolved over the many years during which McDonnell wrote his column, and in the latest version of J not all the examples work as given. We expect the first edition to be of largely historical interest.

Volunteer editors are preparing a revised second edition on the J Wiki. Please help them if you can.

Quickly correlating Kendall

Just posted at Vector:

Quick Calculation of Kendall’s Rank Correlation Distribution Phew! Gordon Sutcliffe shares a fast way to calculate Kendall’s rank correlation frequency distribution.

Curve it like Cauchy

Just posted at Vector:

Curve it like Cauchy Bill Jones & Cliff Reiter use some simple J expressions to draw out the implications of Cauchy’s Integral Theorem – and discover startling and lovely shapes.

And a correction: the recent APL2000 conference was in Bethesda, MD, not Baltimore.