This was originally posted to Catalyst PR’s Facebook page and is reproduced here to make it accessible to people who don’t have Facebook accounts.

For information on the presentations at Dyalog ’14, see http://www.dyalog.com/user-meetings/dyalog14.htm.

Maintainability

The first presentation I would like to highlight from today’s programme is by Gianfranco Alongi from Ericsson AB (Sweden). Those of you who read my posts from Dyalog ’13 last year will know that I am rather taken with Gianfranco’s approach to software development and, in particular, his insistence that it is a software programmer’s sole mission in life to leave a legacy (in the form of code) that is so simple and easy to understand that anyone who comes in later can pick up the ball and run with it, without having to re-invent the wheel and without risking destroying the application. Work smarter – not harder – is his mantra.

Gianfranco’s talk this year was called Let’s Talk about Maintainability!. The background for the talk is that any professional programmer obviously strives for maintainable code, well aware that an unmaintained codebase gradually transforms from a well-tended garden to a dark haunted forest that requires animal sacrifice if left to its own devices. Far too many systems have “that” piece of code – the unmaintained marsh, the mess that causes nausea and elevated blood pressure. Some people swear developers have lost parts of their souls in there and you can hear screaming if you work late enough for long enough…

During the talk Gianfranco explored some of the underlying mechanics of maintainability, presenting a definition of maintainability based on human cognition and sharing a language that might help when talking and reasoning about maintainability. Ultimately any programmer is responsible for maintaining the codebase; However, software entropy is real and we pay in blood, sweat and tears if we choose to ignore it. He insists – and quite rightly so – that maintainability is economics because the Cost of Change (CoC) goes up and up the longer a projects run and it’s measurable as it leads to smaller margins and ultimately smaller profit. Ultimately, you get to a point where it is no longer viable to throw more resources (more people or more overtime) into the mix, and you simply have to re-architect.

The psychology involved in software programming is fascinating! So is the shift from the days of programmers being proud of their ability to write code that other programmers may have difficulty understanding to a world where simplicity in the coding is the ultimate target – in order to address the increasing complexity in the applications.

Statistics

Stephen Mansour (PhD) has taught Statistics at the University of Scranton (U.S.A.) for the past 7 years. He is also working with The Carlisle Group – a company focused exclusively on creating software to support the fast growing mortgage and asset securitisation industry.

The Carlisle Group’s flagship product is CAS, a Collateral Analysis System highly specialised for global asset securitisation markets and used by participants in all facets of the mortgage business, including investment banks, commercial banks, accounting firms, bond insurers and loan originators.

Stephen’s presentation was named Taming Statistics with Limited-Domain Operators and took its offset in a new statistical package he has developed which is using Acre.

(Acre facilitates code management for APLers and was the subject of another talk today. Acre is available as open source software and can be downloaded for free from http://aplwiki.com/acre).

Asked why he felt there was a need for yet another stats package – after all, there are perfectly good packages available in the market, such as R, and even Excel has 87 stats functions, so what exactly is it that a stats package developed in APL can offer that the others can’t, the answer was: Defined Operators!

Stephen then demonstrated the new stats package by making some assumptions with regards to next year’s user meeting and the likelihood of the venue being over-subscribed (or not) based on a number of assumptions and relations.

The package does take advantage of the fact that R already connects into APL and Stephen ended the presentation by saying that the package is currently in beta. He is happy to share, so if you would like to review/try the new stats package please e-mail (Stephen.Mansour@scranton.edu) and specify whether you would like the R version or the native APL version.

The weather predictions have been spot on so far; it’s been another lovely sunny day at Eastbourne – here was the scene this morning at sunrise:

It was another busy day of presentations – read on for some highlights! After dinner tonight the evening will be rounded off with Morten and his Dancing ‘Bots – controlling two robots in parallel.

Discussion Point: Chart Design

As he demonstrated Chart Wizard – a front-end to help building SharpPlot charts – Nic pointed out a few useful tips about chart design:

• Transparency is your best friend
  SharpPlot supports transparency, which not only allows multiple layers of drawings to be readable, but also lightens the global visual impression, making charts more 21st-century
• 3D is not as cool as it looks
  The 2D alternatives (Bubble chart, Contour plot) are generally more readable, because perspective can hide data in automated 3D charts.
• Logarithmic scales are too often neglected
  They can improve readability in many cases, for example stock value, performance comparisons, or wealth repartition
• Box & Whiskers for categorised data exploration
  A very effective tool to explore the repartition of values amongst a un-modelled, yet categorised, numerical dataset.

Paul’s Poncho

The registration packs that delegates received included a stick of rock and a rain poncho generously donated by Optima Systems. As these items were unfamiliar to many from overseas, Paul Grosvenor – Optima Systems’ Managing Director – modelled them for us.

Behind The Scenes

Behind each presentation at Dyalog ’14 is a team of people taking care – hopefully mostly unnoticed – of all the AV requirements. Jason and Jonathan are working full-time in the AV suite and they are being assisted by a rota of Dyalog staff and Liam Flanagan, who has temporarily returned to us for the event, as microphone runners and camera operators. In total there are ten audio feeds and three video feeds, and every presentation is being recorded.

Generally, each presenter has different software and hardware needs and we allow everyone to use their own kit. In past years this has meant that changeovers have sometimes been less than seamless so this time we are experimenting with a system that allows one presenter’s equipment to be set up while the previous session is still taking place – this is giving a really noticeable speed-up in the changeover times.

Over the coming weeks the recordings will be edited and released online. The presentations will be released at the rate of approximately two per week as each generally takes around six to eight hours to edit and needs to be reviewed and approved by the presenter.

And Also …

Some of the many other things we saw and heard today:

• Kai Jaeger told us that software support such as Acre is essential to prevent chaos when there are multiple programmers working on the same project
• Gianfranco Alongi observed that maintenance is not cool, but said that if your product is not being maintained then the chances are it is already dead
• SimCorp maintains 1.7 million lines of APL code
• Stephen Mansour said that the biggest difference between Dyalog and other stats tools such as R is the existence of defined operators
• Nick did not use Powerpoint in his presentation but instead had a text-only equivalent that he wrote himself in coffeescript
• Aaron Hsu announced that his Co-dfns compiler would soon be available on GitHub for download
• Brian demonstrated MiServer 3’s ability to display CIA data
• Bjørn introduced the Dyalog Cryptographic Library which is now available for use

Did You Know?

John Scholes and Geoff Streeter started writing the Dyalog APL interpreter this day in 1981?

Tomorrow…

Tomorrow morning’s schedule includes two Dyalog and two user presentations. The afternoon will be dominated by the Viking Challenge (don’t forget to wear outdoor clothes and shoes that are suitable for walking!) followed by the prize ceremony for the International APL Programming Contest 2014. The two winners (one student and, for the first time, one non-student) will talk about how they achieved their victory. Everyone is encouraged to give this next generation of APLers their full support. The banquet will round off the day.