Last week, I did a quick hack that quite delighted me: I added a way to visually watch the progress of training my MGL-based neural networks inside Emacs. And then people on twitter asked me to show the code. So, it will be here, but first I wanted to rant a bit about one of my pet peeves. Low-Tech In the age of Jupyter and TensorBoard, adding a way to see an image that records the value of a loss…
The updated version of my book "Programming Algorithms" has been released by Apress recently. It has undergone a number of changes that I want to elaborate on in this post. But first, I'd like to thank all the people who contributed to the book or supported my work on it in other ways. It was an honor for me to be invited to Apress as "Practical Common Lisp" published by them a decade ago was my…
Several months ago I had a pleasure to be one of the reviewers of the book The Common Lisp Condition System (Beyond Exception Handling with Control Flow Mechanisms) by Michał Herda. I doubt that I have contributed much to the book, but, at least, I can express my appreciation in the form of a reader review here. My overall impression is that the book is very well-written and definitely worth…
TL;DR RDF* is a new group of standards that aims to bridge the gap between RDF and property graphs. However, it has taken an "easy" route that made it ambiguous and backward incompatible. An alternative approach that doesn't suffer from the mentioned problems would be to introduce the notion of triple labels instead of using the embedded triples syntax. How Standards Should Be Developed Our CTO…
AllegroGraph (agraph) is one of the hugely underappreciated pieces of software freely available to the programming community. Especially this relates to the Lisp community as agraph is one of the largest, most successful, and mature Lisp software projects around, yet it is hardly used by lispers. In part, its relative obscurity may be explained by the following factors: the software is…
Apress — the most dedicated publisher of Common Lisp books, famous for giving the world "Practical Common Lisp" and "Common Lisp Recipes" — has approached me to publish "Programming Algorithms", and, after some consideration, I have agreed. So, the book will be released under the title "Programming Algorithms in Lisp" and with some slight modifications to the content. It was not an easy decision…
(#lisptips on the dynamic nature of CLOS magnified by eval) Since starting programming in Lisp, I always had an impression that using eval is a taboo. Or rather, a cul-de-sac that you never want to touch. When I was only learning Lisp, I had a couple of unsuccessful and rather stupid attempts of utilizing it to bend the language to my view of how it should function — only to learn how it is really…
Recently, I was busy organizing the process of postal delivery of the paperback version of the book to all the interested people. Here, I have created a map showing everyone who has already ordered: I'm glad to see the global geography of readership and all the positive feedback. Thanks a lot! Please, share your thoughts online :) Finally, the book got its own webpage with all the relevant…
I have finally obtained the first batch of the printed "Programming Algorithms" books and will shortly be sending them to the 13 people who asked for a hardcopy. Here is a short video showing the book "in action": If you also want to get a copy, here's how you do it: Send an email to vseloved@gmail.com with your postal address — I'll send you a Paypal money request. Once I see the donation, I'll…
The book "Programming Algorithms (A comprehensive guide to writing efficient programs with examples in Lisp)" has been completed. It turned out to be more than 360 pages in a standard technical book format, with over 100k words (that's 2 NanoWriMos :). It covers more than 100 topics that made it to the TOC — but, actually, more. Phew, making it to this point was quite a challenge... This book is,…
This is a snippet of the "Synchronization" chapter of the book. This is the final chapter of the book, in which we will discuss optimization of parallel computations: whether concurrently on a single machine in and a shared-memory setting or in a distributed shared-nothing environment. This is a huge topic that spans synchronization itself, parallelization, concurrency, distributed computations,…
This is a snippet of the "Compression" chapter of the book. Compression is one of the tools that every programmer should understand and wield confidently. Such situations when the size of the dataset is larger than the program can handle directly and it becomes a bottleneck are quite frequent and can be encountered in any domain. There are many forms of compression, yet the most general…
The state of NLP in 2019. I’m talking with an amazing undergrad who has already published multiple papers on BERT-type things. We are discussing deep into a new idea on pretraining. Me: What would TFIDF do here, as a simple place to start? Him: .... Me: .... Him: What’s TFIDF? — Eric Wallace (@Eric_Wallace_) December 19, 2019 Ми з Мар'яною Романишин розпочали третій набір курсу з обробки…
This is a snippet of the "Approximation" chapter of the book. This chapter will be a collection of stuff from somewhat related but still distinct domains. What unites it is that all the algorithms we will discuss are, after all, targeted at calculating approximations to some mathematical functions. There are no advanced data structures involved, neither is the aim to find a clever way to improve…
This is a snippet of the "Dynamic Programming" chapter of the book. This chapter opens the final part of the book entitled "Selected Algorithms". In it, we're going to apply the knowledge from the previous chapters in analyzing a selection of important problems that are mostly application-independent and find usages in many applied domains: optimization, synchronization, compression, and similar.…
This is a snippet of the "Srings" chapter of the book. It may not be immediately obvious why the whole chapter is dedicated to strings. Aren't they just glorified arrays? There are several answers to these challenges: indeed, strings are not just arrays, or rather, not only arrays: in different contexts, other representations, such as trees or complex combinations of arrays, may be used. And,…
For my book , I had to draw a number of graphs. Obviously, I wanted to have a programmatic way to do that, and Graphviz is the goto-library for that. In Lisp, the interface to Graphviz is cl-dot , but, for me, it wasn't easy to figure out from the manual the "simple and easy" way to use it. I.e. I couldn't find a stupid beginner-level interface, so I had to code it myself. Here's the…
This is a snippet of the "Graphs" chapter of the book. Graphs have already been mentioned several times, in the book, in quite diverse contexts. Actually, if you are familiar with graphs you can spot opportunities to use them in quite different areas for problems that aren't explicitly formulated with graphs in mind. So, in this chapter, we'll discuss how to handle graphs to develop such intuition…
This is a snippet of the "Trees" chapter of the book. Couldn't resist adding this xkcd Balancing a binary tree is the infamous interview problem that has all that folklore and debate associated with it. To tell you the truth, like the other 99% of programmers, I never had to perform this task for some work-related project. And not even due to the existence of ready-made libraries, but because…
This is a snippet of the "Hash-Tables" chapter of the book. Now, we can move on to studying advanced data structures which are built on top of the basic ones such as arrays and lists, but may exhibit distinct properties, have different use cases, and special algorithms. Many of them will combine the basic data structures to obtain new properties not accessible to the underlying structures. The…
This is a snippet of the "Key-Values" chapter of the book. To conclude the description of essential data structures, we need to discuss key-values (kvs), which are the broadest family of structures one can imagine. Unlike arrays and lists, kvs are not concrete structures. In fact, they span, at least in some capacity, all of the popular concrete ones, as well as some obscure. The main feature of…
RUTILS is my take on the Lisp "modernization" effort that adds the missing syntactic and data structure pieces, which became proven and well-established, in Lisp itself or in other languages. The programming field is constantly developing while the Lisp standard remains fixed so some additions, over time, are not only desirable but inevitable, if we don't want to lag behind. Thankfully, Lisp…
This is a snippet of the "Lists" chapter of the book. Linked data structures are in many ways the opposite of the contiguous ones that we have explored to some extent in the previous chapter using the example of arrays. In terms of complexity, they fail where those ones shine (first of all, at random access) — but prevail at scenarios when a repeated modification is necessary. In general, they are…
This is a snippet of the "Arrays" chapter of the book. Arrays are, alongside structs, the most basic data structure and, at the same time, the default choice for implementing algorithms. A one-dimensional array that is also called a "vector" is a contiguous structure consisting of the elements of the same type. One of the ways to create such arrays, in Lisp, is this: CL-USER> (make-array 3) #(0 0…
The next several chapters will be describing the basic data structures that every programming language provides, their usage, and the most important algorithms relevant to them. And we'll start with the notion of a data-structure and tuples or structs that are the most primitive and essential one. Here is a snippet from this chapter. Data Structures vs Algorithms Let's start with a somewhat…