Not All Heroes Wear Capes

On Friday 15 October, the SERV S&L was presented with The Queen’s Award for Voluntary Service by the Lord Lieutenant of Surrey. Geoff Streeter was one of 20 volunteer SERV S&L members who attended.

What Is SERV S&L?

SERV S&L (Service by Emergency Rider Volunteers for Surrey and London) are a charity organisation, made up entirely of volunteers, comprising motorbike riders, car drivers, controllers, and fundraisers. They transport blood products, urgent samples, medical supplies, and donated breast milk to hospitals and milk banks across Surrey & London, as well as carrying out a daily delivery of blood to the Air Ambulance service that covers Kent, Surrey, and Sussex. They support the regular delivery rounds that the NHSBT (National Health Service Blood and Transport) have in place; unlike the NHSBT, SERV S&L also operate throughout the night. All of this is provided free of charge to the NHS, releasing more money for patient care.

What Is The Queen’s Award for Voluntary Service?

QAVS (The Queen’s Award for Voluntary Service) celebrates the outstanding work of local volunteer groups across the UK. Created in 2002 for Queen Elizabeth II’s Golden Jubilee, QAVS awards shine a light on the fantastic work of voluntary groups. QAVS awards are the highest awards given to local voluntary groups in the U.K. (they are the equivalent of a personal MBE) and they are awarded for life.

Geoff’s Involvement with SERV S&L

A Personal Recollection

At the end of 1980, Paul McCann had a relation who could not get an urgent sample transported to the testing lab until the next morning. He was frustrated by this and organised a meeting to see what could be done, the result of which was that a group of advanced motor cycle trainers from a (now defunct) group called Star Rider decided to try to run a delivery service for blood/samples at night. I was not at that meeting but I heard about it from a fellow member of the Laverda Owners group; I made it to the second meeting (on 8 December 1980) and have been involved ever since. We obtained a room with a couple of bunks in a wooden building owned by MEFAS (Malden Emergency First Aid Society) and a telephone line, and started operating in early 1981.

The main distribution point for blood is located in Tooting and serves London, Kent, Surrey and Sussex (we have partner organisations in Kent, Sussex and Wessex). We do a main nightly run with typically 6 to 10 boxes down to an arranged change point for Kent and Sussex. We also partner with similar organisations across the U.K., and have occasional relay runs, for example, from Edinburgh to central London (I think that’s the longest that we’ve been involved in). More common are runs from Bristol. We typically shift 20 boxes a night and samples in the other direction and have about 8 riders/drivers on shift every night.

Financially, we get support from some Masonic Lodges and business groups. They prefer to buy bikes for us, and Citroen have given us a car (DS3) on permanent loan. We are in the process of acquiring/refurbishing a scout facility in Sutton to provide a base for the bikes/cars/van as well as for volunteers who live on the periphery of the area. We also raise funds by box waving outside supermarkets, garden centres, Brooklands, Waterloo Station, etc.

I started with the group as a biker, and used my Laverda 750, Laverda 1200 and Honda 650 Turbo to deliver blood and samples from 1981 until 1990, when I switched to car deliveries (which I continued to do until last year). I also acted as Treasurer from 2006 until 2010. I have been one of the controllers right from the start [Ed.: Controllers orchestrate the logistics of a shift; hospitals and partner groups place their orders and riders and drivers are dispatched as required – accurate scheduling and data logging are required to ensure efficient co-ordination and communication so that each run can be completed reliably], a role that has changed a lot over the last 40 years. In the early days controllers needed to be physically present with the one rider and the telephone. Then we moved to using pagers (but still needed to be present in the hut/sports centre) before everything changed with the advent of mobile phones – I now control from home. The expectation is that volunteers do one night a fortnight, but a shortage of volunteers relative to growing demand means that for a few years now I have been doing at least one shift a week.

Final Word

Congratulations Geoff, 40 years of volunteering for such a worthy cause is a fantastic achievement. All of us at Dyalog Ltd are really proud of your contribution.

To find out more about the amazing service provided by SERV S&L, including how to make a donation, visit https://servsl.org.uk/.

Welcome Karta Kooner

Karta joined Dyalog in April, and is yet to meet anybody in person although he’s been told that this is not necessarily a bad thing! After completing his doctoral degree in theoretical physics, Karta stumbled upon Dyalog and APL entirely by happenstance. Being often captivated by things that look unfamiliar to him, and having an interest in most things, it was a code golf question that was answered in a strange, yet mathematical-looking language that took him to the profile of the poster, who happened to mention they were employed by Dyalog and currently hiring. He sent an email enquiring about the opportunity and, several remote interviews later, was happy to be hired as a C/C++ developer working on the interpreter.

Karta is one of the few members of the team that knew no APL whatsoever before joining and has been very impressed by Dyalog and APL thus far; he is very much looking forward to seeing how far the language can be taken, with an eye to further developing and potentially encouraging its use in academia and other technical fields of study.

In his spare time, Karta enjoys expanding his knowledge of both scientific and technical pursuits, and tinkering around with software and hardware systems, amongst his eclectic interests. When not found reading papers or learning an unfamiliar branch of mathematics, he will be caught thinking of a new engineering project to occupy his time, or stumbling through learning a new language, or maybe just delighting in the latest vixra paper.

News and Recommendations Regarding Dyalog Versions 17.1, 18.0 and 18.1

Background

Dyalog version 18.0 contained the largest number of optimised algorithms in the history of Dyalog APL. Unfortunately, since its release, we have found that our process for review and testing of optimisations was insufficient to cope with the quantity and nature of the optimisations. Many of the new algorithms had edge cases that escaped both the existing regression tests and the new tests that were written as part of development.

In August 2020, after the issues were reported following the release of Dyalog version 18.0, we issued a caution against the use of version 18.0 in production. We added significant additional testing during September and October, and subsequently lifted the caution in November. In April 2021, a user encountered an additional defect leading to incorrect results in a rare case of membership (), and in June a crash in an extremely rare case of “where” (monadic ). Since then, our own internal testing has found a defect in interval index (dyadic ).

Current Status

We have made patches available as defects have been detected and fixed, and “Issue 4” of version 18.0, made available to all users on 22 June 2021, includes fixes for all known issues with optimised code.

Download Dyalog version 18.0 Issue 4: Commercial users  Non-commercial users

At this time, we are executing two high priority projects, one aimed at increasing safety in the short term, the other at completely eliminating problematic optimisations within a few months:

  • We have further increased our internal testing of version 18.0, to verify the correctness of the optimisations that are still in the distributed product.
  • We are holding back the release of version 18.1, which was originally scheduled for release this month, while we remove most of the optimisations that went into version 18.0. We hope to release version 18.1 before the end of the 3rd Quarter of 2021, but will not let it out the door until we have complete confidence in this new version.

Recommendations

Dyalog Ltd recommends that users of Dyalog APL take the following action:

  • If you are using version 17.1 or earlier, plan to skip version 18.0 and upgrade directly to version 18.1 when it becomes available.
  • If you are using version 18.0, apply the latest patches or reinstall using Issue 4 when it becomes available. Continue to monitor our DSS e-mail broadcasts and apply patches quickly if we should find and fix any further issues that you think might impact your application. When version 18.1 becomes available, plan to upgrade to it at your earliest convenience.

Support for Versions 17.1 and 18.0

Considering this extraordinary situation, we have decided to extend support for version 17.1 for one additional release cycle. In other words, version 17.1 will be supported until we release the 4th subsequent version of Dyalog APL. Note that we are about to provide an updated version 17.1 installer (“Issue 3”) which collects all updates to version 17.1 since the original release.

Version 18.0 will be supported for the normal number of cycles, that is, until we release the 3rd following version. However, Dyalog Ltd recommends upgrading to version 18.1 as soon as it becomes available and you are able to schedule the upgrade.

Non-Commercial Versions

Given the nature of these defects, it is our intention to update our non-commercial distributions of version 18.0, although this process may lag behind the distribution of patches to clients paying for support by some weeks.

Conclusion

We apologise for the significant inconvenience that we know this is causing for some of you and thank you for your patience. We have made significant changes to our internal procedures regarding risk assessment, verification, and testing requirements for changes to existing primitive functions, to avoid a recurrence.

We do expect to re-apply those optimisations that we believe provide significant performance benefits to justify the risk of making changes over the next few releases, using new processes.

Sincerely,

Morten Kromberg
CTO, Dyalog Ltd.

APL Seeds ’21: Wednesday 31 March

Last Wednesday we hosted APL Seeds ’21, an event for those just starting their APL journey. Although we knew we had a good programme with some exceptional presenters in place, we very quickly had to increase our Zoom webinar limit to accommodate the 287 people who registered to attend! We were surprised and excited by the demographic, spanning 32 countries and with the vast majority having only basic or no APL experience.






The meeting started with a brief introduction from Dyalog’s Managing Director, Gitte Christensen, who shared her initial “Eureka” APL moment and gave some examples of situations in which APL is used today. Richard Park then took us on a whirlwind tour of APL’s past (including the very cool 1975 APL demonstration!) before demystifying the “beautiful squiggles” that define APL and introducing the modern resources that are available for learning APL (for a summary of these see the suggestions for learning resources available on our website).

The main presentations began with Rodrigo Girão Serrão giving a basic introduction to APL functions and syntax. Using the example of manually justifying text, he showed just how natural it is to process data in arrays by combining a few functions and operators. His initial exploration using a small snippet of text worked instantaneously and without issue on a whole book. After seeing this, hopefully you’ll feel an urge to learn some more – either because you got hooked (like Rodrigo did!) or simply because you want to learn how to think in an array-oriented way, which is very relevant in many situations today, such as when working with GPUs.

Martin Janiczek used a real-life example from the market insights and consumer trends company that he works for (GWI). Despite being a self-described “APL baby”, having learned APL for only around a month, he was able to get to grips with the tree structures that he wanted to use, and talked about how learning APL led him to change his overall approach to the problem. He achieved a highly-performant working prototype in two weeks and with only 172 lines of code, despite starting from the position of a complete APL beginner. Although ultimately his APL model was not taken into production, it inspired a complete rethink and new approach in the eventual product.

Conor Hoekstra (NVIDIA) describes himself as “not an APLer but a big fan”, and his enthusiasm is obvious and contagious! His explorations in APL are YouTube famous, and here again he deftly shows how APL can be used as a tool of thought to explore problems from many different angles with relative ease. He went through multiple different solutions to writing an All Equals function (is every element in a list the same as every other element?), playing with different primitives and comparing the performance of the solutions.

The final presentation came from Tomas Gustafsson, creator of the stunning Stormwind boating simulator. Tomas introduced the technology behind the 3D engine that he uses for his simulator, explaining the code that makes it all happen, before walking us through creating some simple 3-D shapes (a rotating triangle and an icosahedron) and the pitfalls that this entails. From the comments we know he seemed to inspire several members of the audience to want to know more… so for those of you that do, his code examples will soon be available from the APL Seeds web page.

We hope everyone found the event useful and enjoyable (the feedback seems to indicate that you did – thank you!). Relevant materials have started to be uploaded to the APL Seeds ’21 webpage – this page also includes links to recordings of the presentations, which are all on dyalog.tv:

 

Welcome Rodrigo Girão Serrão

The story of how Rodrigo got his first internship at Dyalog is, in his opinion, a textbook example of serendipity. As 2020 started, Rodrigo began actively participating in an online code golf community, where people try to solve programming challenges in as few bytes of code as possible. Whilst his golfing skills were possibly lacking, the challenges he posted were usually well accepted. Posting many challenges meant Rodrigo got exposed to answers in all sorts of programming languages, from C, Java, Python and JavaScript, to Jelly, 05AB1E, Husk…and APL. Because of the context and the aspect of it, Rodrigo first thought APL was one of those “esolangs” and not a serious programming language.

Rodrigo’s fascination with APL led him to start frequenting The APL Orchard chatroom, where a small number of brilliant people convened to discuss all things APL. Here he met Adám Brudzewsky, who was keen on teaching APL to newcomers, and so began Rodrigo’s journey to learn APL.

His interest in APL kept growing, and he found it to be a simple and expressive language that also incorporated his affinity with mathematics. One day, while lurking in The APL Orchard, Adám asked Rodrigo if he would be interested in taking an intern position at Dyalog…a few emails later it was established that Rodrigo would work as a part-time intern at Dyalog during the Summer of 2020. This enabled Dyalog to make the most of Rodrigo’s skills in teaching and technical writing, and meant Rodrigo could indulge his passion for sharing knowledge about mathematics and programming while still finishing his MSc in Applied Mathematics. After his internship, Rodrigo took some time to complete his MSc thesis before returning to Dyalog to finish what he had started and hopefully to take part in many other interesting projects. When he is not working for Dyalog, Rodrigo may be found leading a Portuguese APL meetup, writing a blog post for his website (mathspp.com), or maybe leading a workshop or course. Other than working, Rodrigo likes to spend time with his loved ones, read fantasy books, eat chocolate, and watch silly comedy movies.

Welcome Shuhao Yang

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Shuhao joined Dyalog straight after he completed his Master’s degree in quantum computing, which happened to be during the second COVID-related lockdown in the UK. This has given him a quite unusual experience of starting a career as he has yet to meet a single member of the Dyalog team face to face! Shuhao obtained his Bachelor’s degree in mathematics – although he was interested in computer science, he studied mathematics as a way of looking for the root of CS and computing. He has broad interests across different software including Matlab, Python and LaTeX and has developed a solid knowledge on C++.

Shuhao enjoys the romantic theories in computer science and always wanted to work in one of the summit areas of CS – compilers, graphics and operating systems. He’s very happy that he now has the opportunity to work on the Dyalog APL interpreter.