Dyalog ’19: Thursday 12 September

Dyalog Pictures Ltd?

After a wonderful banquet dinner bonding with fellow teammates of last night’s Viking Challenge, we were invited to the Jorns Auditorium for the world premiere of our movies from earlier in the day. The screening and awards show was a roaring success with everybody being surprised and thrilled at the quality of what came out from the editing room. We would like to thank Filmteambuilding.dk for an incredibly enjoyable afternoon and evening.

How do I… in APL?

In another world premiere, Adám Brudzewsky introduced us to APLcart this morning. This is the new answer to the question “how do I… in APL?”. Luckily Adám’s presentation strategy of asking the audience for functionality to search for was a win-win – if APLcart had it then we were impressed, and if not Adám had a new item to add to APLcart. Try it now and see if APLcart has what you’re looking for. If you can’t, Adám invites you to email the functions you want to see to adam(AT)aplcart.info.

Richard Park then gave his third and final presentation of the week on the theme of using APL for education. He showed us how you can quickly and easily create Dyalog Jupyter notebooks and recommended using them for how-to, instructional documents and problem sets for students. You can view and download his presentation (which is a notebook) from GitHub, and interact with the live running notebook by clicking this button → .

Tomas Gustafsson tells the Irma story

We then had the final talk of the User Meeting. Tomas Gustafsson, creator of the Stormwind boating simulator, told us the fascinating story of the Finnish ship M/S Irma. It disappeared while travelling a common route in 1968 and became one of the greatest mysteries in Finnish maritime history. Eventually some wreckage was found near Åland and Tomas was able to use APL, reconstructing possible paths of the debris via simulation, to make an educated guess of where to search for the main wreckage.

Lastly Gitte expressed to us how enjoyable the week had been, and all in the audience seemed to agree. We thanked Helene, Karen, Jason, Fiona and all of the staff at Konventum for their hard work “behind the scenes” to make the User Meeting run smoothly.

For the last afternoon of the User Meeting three final workshops were held. Two focused on technical software development issues, with Morten and Josh answering users’ questions related to using text-based source with ]LINK and Git. Andy Shiers and John Daintree were generally helping users with application-related issues, but were especially helpful to some of the young new users of APL. Some of our delegates took on another challenge in the workshop on code golfing.

I think it is safe to say that we have all thoroughly enjoyed this week. You can look forward to seeing our commercials from the Viking Challenge as well as recordings of talks from this week at some point in the future on dyalog.tv.

Dyalog ’19: Wednesday 11 September

Floaty balls

In contrast with Monday night’s brain-bending puzzles, last night there was some lighter entertainment as Richard Park presented his molecular dynamics framework APLPhys. He showed us how elegantly APL could express mathematical equations and we joined in his fascination watching simulations of little balls flying around on his MiServer based graphical interface.

APL for every kid

Roberto and students from Liceo Scientifico GB Grassi Saronno

This morning we got to hear from Roberto and his students again. Pietro, Alessandro and Gabriele told us how after they were shown APL in school their interest was sparked to the point that they would write APL in other, slightly more dull lessons. They gave us more details on their competitive league scoring algorithm which was used in Monday evening’s contest. Lastly they expressed how APL’s ability to have you think differently led them to develop their puzzle competition platform called MathMaze. They had familiarity with Python but were new to APL, so they used Py’n’APL to make Dyalog communicate with a python-based Django server. In that way, MathMaze contestants could enter either a direct puzzle solution, or an APL statement which is evaluated on the server to solve the puzzle.

Afterwards Stephen Taylor led the Young APLers panel. To begin he introduced us to Josh David from the small town of Scranton, PA. We learned how he started working with APL at 15 years old after being introduced to it by his neighbour Paul Mansour of The Carlisle Group. Next was James Heslip from Optima, telling of his discovery of programming through Visual Basic. During and after university he wanted to pursue computing but keep the maths aspect of his work in the future. After meeting Paul Grosvenor he managed to convince Paul to take him on as an apprentice at Optima, and now APL allows him to write programs using mathematical notation. Yuliia Serhiienko from Ukraine came next to the stage, and said how she loved mathamatics in school but never imagined becoming a programmer. She had been an actuary in a previous life but, in the end, her transition from Excel macros to APL turned out wonderfully. Alve Björk, last year’s competition winner, claimed to spend more time reading about programming languages than actually programming. He said that in many languages he will think of a program but not write it. However, since APL is terse he actually sometimes tries it out when he thinks of a program. Alve also stated that he found it interesting that when you have a problem, in APL it’s not the first thing you do to go online looking for a ready made solution.

The young APLer’s panel. From left: Stephen Taylor, Alve Björk, Yuliia Serhiienko, James Heslip and Josh David

All of the panelists discussed the importance of having a teacher and being able to ask questions. It was suggested that some kind of mentor system for APL could be fostered. Once again the idea of “spreading the gospel” and getting APL in front of more people was brought up, and how it may be necessary to do this in order for the community to grow – as much as some of us would like it to remain niche.

The 2019 APL Problem Solving Competition

Professional prize winner Torsten Grust

Finally, the moment we’d all been waiting for: the prize ceremony for this year’s problem solving competition. Brian Becker talked about how we had made the leap to “eat our own dog food”, having built and hosted the competition website using MiServer (you can still see it at dyalogaplcompetition.com). Many technologies came together so that Dyalog could have the Phase I “one-liner” problems automatically validated in collaboration with TiO.Run. We saw some stastics about registrations and submissions, and heard about the extremely high quality of both Phase I and Phase II entries this year.

Then Gitte presented the top professional and student competition winners with their prizes. Torsten Grust expressed how much fun he had thinking about the problems and how clever he felt when he managed to come up with his solutions.

Grand Prize winner Jamin Wu

The Grand Prize winner Jamin Wu told us about how he discovered programming when he was looking into ways to solve problems using computers – something he still needs to do despite being a medical student – and how he had found the APL family of lanugages via the project Euler website. Jamin then took us through some of his solutions, including his incredible invertible tacit functions for tap encoding and decoding. He expressed how nice it had been to think about his implementation of the Romberg method of integration by solving the problem with a pen and paper first, and then implementing the refined solution at the end, since writing the APL was so cheap in terms of effort. We were enthralled by his brilliant explanations and incredibly impressed by his well considered problem solutions.

After lunch we were made extremely busy in the Viking Challenge. The delegates were split into teams and had to make short commercials emphasising a certain aspect of APL to a particular audience. We expect to see some oscar-winning performances at the screening after the banquet dinner – so now it’s time to get on my Sunday Best ready for the prize acceptance speech I expect to make.

Dyalog ’19: Tuesday 10 September


Last night Roberto Minervini and his students Pietro Pio Palumbo, Gabriele Meroni and Alessandro Laselli of Liceo Scientifico GB Grassi Saronno conducted A Puzzle League – sneakily introducing us to another APL. The delegates were divided into teams who competed to solve 18 maths and logic puzzles, which could be solved both using APL and with good old pen and paper. The scoring system rewarded teams who solved puzzles that other teams did not solve, but it was soon clear that the real challenge was solving the puzzle whatsoever in many cases. The furious cognitive battle lasted long into the night but eventually the team “AdamsAPL” (Adám did not choose the name) beat “MKTeam” (Morten may well have chosen the name) to prove that, although Morten Kromberg is the CTO, he should be glad to rely on the problem solving capabilities of Dyalog’s employees.

Roberto and Pietro introduce another ‘APL’

Application Station

Marshall shows us a bit of Dyalog ‘under the hood’

This morning the second day of talks commenced. While the first talk of the day had Marshall Lochbaum melting brains with the details of utilising CPU vector processing (among other techniques) for implementing fast reductions, the majority of the day’s talks focused on various tools for developing software applications with Dyalog.

Richard Park and Michael Baas gave an update on recent developments of the statistical package TamStat. The creator, Stephen Mansour, couldn’t be with us this week as he is using TamStat to teach his class at the University of Scranton, PA.

Erik Wallace gave us a view of the wide range of functions available in his cryptographic library Mystika. His talk mentioned promising work in combination with Aaron Hsu’s co-dfns compiler to give speed ups, as well as some of his own work on algorithms and implementation. Erik also expounded on some non-cryptographic use cases such as high precision squaring and inverses.

Stig Nielsen of SimCorp

Stig Nielsen told us how SimCorp is moving Dimension to the cloud – an undertaking which requires that the business logic within its 2.5 million lines of APL code be moved from the desktop application to the server and run on multiple instances of Dyalog within a .NET process.

Asset and Liability Management has been getting more popular as the legal landscape changes and SimCorp Italiana have been swift to account for those needs. Francesco Garue gave an impression of the complexity of ALM and how SimCorp Italiana have been trying to tame their “pretty messy scheme” by, for example, removing the dependency on system-specific databases or tables.

Another asset management system was presented by Claus Madsen of FinE Analytics. Claus has been using Dyalog since version 6 so he has seen the evolution of APL user needs over the last thirty years. He showed us how he has been using .NET classes to allow his APL solution to integrate with other languages used by those he is working with, using an object oriented model to handle settings for various types of financial data.

Gooey GUI

Brian Becker shows us the HTMLRenderer

The HTMLRenderer has been developed to enable easy creation of cross-browser user interfaces using web technologies. Brian Becker drew some analogies between his granddaughter and HTMLRenderer over their respective developments, from sometimes making a mess (SYSERROR) to becoming more able to communicate over time (WebSockets). He then introduced some recent changes and additions to the way the HTMLRenderer is used in Dyalog 17.1. However, he also explained that MiServer sites would need no change to their code in order to run as a desktop application using the HRServer (HTMLRenderer Server).

Josh David has recently transferred from Dyalog user to Dyalog employee. Neatly segueing from Brian’s talk, he gave us a demonstration of the tools he has created which use the HTMLRenderer to quickly and easily create graphical elements in the Dyalog session.

Josh David demonstrates his Easy GUI

And now for something completely different

Somehow COO Andy Shiers of Dyalog keeps improving the fireside chat, and this year has reached version 5! Jokes aside, his fireside chats are an opportunity to address a few points which might not fit into the scope of other individual talks. This year Andy informed us about why it is now really important that the interpreter knows its serial number, and gave us his usual smorgasbord of tips on subjects such as: the new Windows “backtick” keyboard enhancement, resizing the language bar, the memory manager I-Beam (2000⌶) and using ⎕NINFO on directories where there are inaccessible subdirectories. In return he asked the we send him examples of APL errors which would be made clearer with better DMX messages.

Nathan Rogers creates Excel spreadsheets using Dyalog all the way from Colorado

Excel and APL: A match made in Windows – now available cross-platform. As new recruit Nathan Rogers demonstrated, since modern Excel spreadsheets are zipped XML documents using the OOXML specification, Excel spreadsheets can be created directly from APL arrays on any platform. Unfortantely Nathan could not be here in person due to an important performance of Argentine tango with his wife conflicting with the User Meeting. However, he was still able to present via video-link – what a time to be alive!

Don’t forget that tomorrow we will be live streaming the prize ceremony for the 2019 APL Problem Solving Competition on dyalog.tv from 11:00 until 12:00 (09:00 to 10:00 UTC).

Dyalog ’19: Monday 9 September

Dyalog ’19 talks begin

As usual, we began the series of User Meeting talks with a warm welcome from Managing Director Gitte Christensen. This year Gitte’s message felt somewhat spiritual as she described the lore of Thor’s hammer Mjölnir and its place in formal ceremonies. The choice of logo for this year’s User Meeting feels appropriate to the current zeitgeist: the desire to make some order from the chaos we may feel around us. You could feel a sense of hope in hard times.

Gitte welcomes us to Dyalog ’19

Hard and sad times have certainly befallen us recently and we remember two APLers who have sadly passed away this year. Harriett Neville who was supposed to attend the User Meeting, and John Scholes who left us in February. However, we also say hello to new faces at this User Meeting – Josh David and Nathan Rogers who were hired to form our new US consulting team.

In consideration of new APLers, Gitte also gave a call to arms that we should “spread the gospel” about APL. She expressed how Dyalog is making it easier to introduce people to APL by having unregistered copies of Dyalog available for non-commercial users in the near future, and also by encouraging people to share their APL tools freely online using services such as GitHub.

Morten shows us the road ahead

This was shortly followed by a road map of future Dyalog development from Technical Director Morten Kromberg. He also emphasised how Dyalog is making APL easier to find for new people, this time mentioning the APL Orchard Chat room; the Dyalog Webinars which have been running for about 2 years now; our talks in the wider programming community at events like LamdaConf and FunctionalConf; and of course the open source APL projects as Gitte had mentioned.

Morten also described how we have been working and continue to work to make APL applications easier to deploy, maintain, test and integrate with other frameworks and development processes.

There were no surprises in JD’s demonstration of the .NET Core Bridge. The functionality in terms of the .NET Framework remained, but JD showed us what it would look like if .NET “was as portable as they tell us it should be” and could be used on Windows, MacOS and Linux with the same APL code.

Marshall took us in a more technical direction, although still pointed towards the future of APL. He showed us the new operators constant , atop and over which we can look forward to in version 18.0. He also gave the suggested new nomenclature for the several types of function composition which will be available when these function-composition operators are released.

Marshall introduces new operators for Dyalog v18.0

Tommy Johannessen has been running his one-man company for some decades now, and we got to see a great user story as he demonstrated the interface to his school lunch system SkoleMad. It enables the delivery of 20,000 meals daily to 100,000 students!

Morten and Adam teamed up again to bring ]LINK to a wider audience and emphasize the importance of using text-based APL source files to modernize your APL development workflows. This is also a vital tool if you want to share your code easily with services like GitHub.

Paul Mansour demonstrates Git integration with AcreTools

The theme of modern APL development continued seamlessly as Paul Mansour of The Carlisle Group presented a Git workflow for Dyalog APL using the Acre project management system. He demonstrated using AcreTools user commands and broke down a Git workflow into something accessible even to people who are new to Git and may find it slightly daunting to use.

The co-dfns compiler is a staple of the Dyalog User Meetings at this point. Aaron Hsu’s PhD project allows APL code to run fast on GPUs, and this year he was clearly excited to show us some of the revelations that have come from the development of co-dfns. These revelations came in the form of some quite high level development concepts for us to chew on and there are sure to be some interesting conversations as a result.

Aaron Hsu pontificates

The future is here, the future is now and the future is cross-platform. Richard Smith brought us yet another tool in the future tool box for Dyalog: Cross-Platform Configuration Files. The project is in early development and so the majority of the talk became an interesting debate into the pros and cons of various ideas for the format. XML, JSON, YAML or another – who will win? Only time will tell…

Geoff Streeter regales and informs about shared code files

Geoff told us the story of how a request to have functions loaded on demand led him to the germ of the idea and eventual implementation of shared code files. The audience was attentively, silently listening and the air of the Damgårdsalen was that of a village gathered around listening to their elder.

Richard Smith returned to show us some datetime functions to help us find out whether or not it is yet Christmas (SPOILER: It’s not Christmas yet). His slick demonstration reassured us that handling dates and times in Dyalog can and will be as painless as the idiosynchrosies of time and calendars permit – again after some details have been worked out.

Now we are adjurning for dinner. Later this evening we will be puzzling some puzzles in the APL Team Contest, hosted by members of Liceo Scientifico GB Grassi Saronno (a scientific high school in Italy). Don’t forget to check out tomorrow’s blog post to see how things went!

Dyalog ’19: Sunday 8 September

Welcome back

This year once again the Dyalog User Meeting returns to beautiful Elsinore in Denmark. The historic seaside city is home to Kronborg castle, famously immortalised in Shakespeare’s Hamlet – and Kromberg castle, where Morten lives. We are holding the user meeting at Konventum in the western outskirts of Elsinore. It features winding corridors adorned with contemporary Danish art and many comfortable seating areas conducive to social engagement, so we hope that delegates will find themselves meeting new people and conjuring beautiful new ideas as the week progresses.

Social spaces are everywhere at Konventum


Today six half-day workshops were held, with topics ranging from source code management and graphical interfaces to cutting-edge APL techniques which have become available in the last decade of APL extensions in Dyalog.

Morten and Adam’s morning workshop focused on helping users collaborate on code with text-based source files. Adám introduced the ]LINK user command and Morten showed the way with Git – both guided the adoption of these technologies with worked examples.

We saw the delegates shine with their understanding of APL in the workshop on grouping and processing text. Nic helped us to understand the differences between partition and partitioned enclose. Powerful search and replace with ⎕R and ⎕S was elucidated by Richard Smith and, in this section, the ability of the participants to ask exactly the expected questions made the progression to understanding relatively smooth.

Brian Becker of the tools group and new recruit Josh David teamed up to introduce users to the new HTMLRenderer, which allows APLers to use web technologies to create cross-platform graphical user interfaces in Dyalog.

Adám points us in the right direction with function trains

Function trains are a relatively recent addition to the APL syntax, and with their terseness people can find them daunting both to read and write. However, once again we saw delegates stepping up to the challenge and finding creative ways to solve problems. It was a joy to see the creativity on display and the variety of approaches people took to solving the problems using only function trains. Marshall gave some details on the use of the rank operator , and despite this formidable challenge of understanding, by the end people were starting to grasp the power of this operator.

The morning’s HTMLRenderer workshop was mirrored by another GUI workshop in the afternoon. Michael and Chris Hughes worked to help people take their ⎕WC graphical interfaces, for Microsoft Windows, and get them to work on MacOS and Linux by using their qWC functions.

The mainframe is now the cloud, and with the ability to share great computing resources has come the need to learn another sizeable set of technologies. Morten and Norbert Jurkiewicz helped to clear some of the fog on this recent computing paradigm.

Things to come

For the rest of this week there will be many presentations from Dyalog employees and users – as well as an APL Team Challenge, the Viking Challenge, and of course the Banquet dinner on Wednesday evening.

We will be continuing to publish short daily recapitulations to give you a flavour of the talks and events of each day. However, if you are too impatient even for that, we will be streaming Monday morning’s talks live from 09:00 to 10:45 (07:00 to 08:45 UTC). Also, on Wednesday morning between 11:00 and 12:00 (09:00 to 10:00 UTC), the 2019 APL Problem Solving Competition will be concluded as this year’s grand prize winner Jamin Wu will be presented with his prize and will talk about his experience with the competition. These streams will be available to watch live on dyalog.tv, so make sure to tune in if you don’t want to wait until the talks are published later this year.