fidzu : debian

The twenty-first release of the qlcal package arrivied at CRAN just now, and has been built for r2u. It comes a week after the 0.1.2 release.

qlcal delivers the calendaring parts of QuantLib. It is provided (for the R package) as a set of included files, so the package is self-contained and does not depend on an external QuantLib library (which can be demanding to build). qlcal covers over seventy country / market calendars and can compute holiday lists, its complement (i.e. business day lists) and much more. Examples are in the README at the repository, the package page, and course at the CRAN package page.

This releases includes a one-line fix we also sent upstream as a now-merged PR: one of the calendar files added in QuantLib 1.43 also needed to include the vector header file. And every compiler appears to be lenient (QuantLib itself has fourty different continuous integration jobs, we test with all builds at r-universe) apart from the CRAN macOS x86-64 machine. Sigh. This is now fixed. We also included a neat little local trick I should blog about: if the build is detected as a non-CRAN local build (simply by checking for a .git directory) then compiler flags can be updated to quieten the build. We cannot do that in the package because we would get our fingers slapped over so-called 'non-portable compiler flags'. Sigh again. Anyway, the trick helps.

The full details from NEWS.Rd follow.

Changes in version 0.1.3 (2026-07-21)

• Add missing 'vector' header to new IslamicHolidays calendar file, also PRed upstream and merged there

• In local compilation out of git repo add additional compiler flags

Courtesy of my CRANberries, there is a diffstat report for this release. See the project page and package documentation for more details, and more examples.

This post by Dirk Eddelbuettel originated on his Thinking inside the box blog. If you like this or other open-source work I do, you can sponsor me at GitHub.

21 Jul 2026 1:18pm GMT

(no, this isn't a blog post about Joy Division songs)

Last time I wrote about Interzone, I was discussing issue #294, the first published under new management in a paperback-sized format ("JB6"). The format and presentation of the magazine was fantastic: it fit in a lot of my pockets, and was packed with 15 stories as well as the regular columns, in full colour with fantastic layouts and illustrations. Sadly there was only one more physical issue before Interzone was forced to become a digital-only publication.

I don't want to dwell on the sad necessity to move to digital. Interzone continues on, celebrating the milestone issue #300 in 2024. Subscriptions are managed via Patreon. Issue #305 just came out.

Instead I wanted to write a small bit about how I engaged with the paper magazine, and the difficulties I've had trying to engage with not just Interzone but any magazine-style publication in a digital context.

With most fiction, I read linearly: start the beginning and read to the end, in order. That works well for me with e-readers. But for magazines (and most non-fiction) I don't, I jump around: usually starting with the table of contents, I might pick a short column to start, or jump into the middle of the "book reviews" section to read about a specific book. I might skip sections entirely. I find it very difficult to read like this with an e-reader. I think this is partly because I reference the depth of the paper book or magazine, its thickness, to orient myself. But it's also partly the limitations of e-ink.

For print-Interzone, I used to start by inserting a small piece of paper inside the cover (the delivery slip was ideal). On this I listed the stories within and ticked them off when I read them (sometimes I double-ticked if I really liked a story). That helped me to remember, perhaps months or years later, whether I'd read all the stories or not, and which I liked. I could do something similar on some e-readers: the Remarkable for instance. But it's far from convenient to do on most e-ink devices.

Interzone digital is available as both ePUB, the most common format for e-books, and PDF. For reading on my regular Kobo e-reader, PDFs don't work very well at all. I think this is generally true of most e-readers.

Interzone was (and is) a well-designed magazine. The value of it was not just the content of the text, but the context: how the stories were presented; the accompanying art (most often colour in recent decades), but also the typesetting. ePUB doesn't specify much of that stuff exactly: it leaves that up to the client and the client's preferences. And there's a lot of advantages to that: Prefer a different font face or size? No problem. And most importantly for accessibility: If reading in ePUB makes Interzone available to more readers then that's a great thing. But sadly a lot is lost, IMHO.

The solution I'm trying is to read the PDF version on the iPad Mini I resurrected earlier in the year. Despite being an Internet tablet, since it's not really usable for browsing the web anymore it's strangely still a distraction-free device. In fact it's pretty much single-purpose for reading Interzone and the odd other book which benefits from being read as PDF. I can appreciate the stylistic choices made in the page-setting as they were intended; I can quickly jump around the issue without waiting for an e-ink refresh; I get full colour; and whilst it would be tiring to read for a long time on the iPad screen, for the length of articles or stories in a magazine, this isn't a problem.

It's not a solution for tracking what I've read (that version of ipadOS is too old to support clumsily scrawling on PDF pages with your fingers, at least in the Books app) but it otherwise seems to work well, so I'll see how it goes.

20 Jul 2026 9:26pm GMT

When you pass an AWS certification exam, sometimes it can extend the life of related lesser AWS certifications. But I could not find an illustration of exactly which ones, so here's an up-to-date diagram:

Figure: Renewal relationships between AWS certifications.

Each arrow is a 'renews' relation - there's no obligation to pass lesser exams before the harder ones, but you could also follow the arrows backwards if you want to learn easier material before sitting the more difficult exams.

I have made two important simplifications to the graph:

1. The 'Advanced Networking - Specialty' certification is being retired soon, so I've omitted it entirely. The last date to take that exam is 25th August 2026. But Specialty certs don't renew anything else anyway.

2. I have left out transitive relationships in order to simplify the graph - so e.g. if you pass a 'Solutions Architect - Professional' exam, it also renews any Cloud Practitioner certificate you might hold, even if you do not currently hold the relevant Associate certificate.

You also have the option of sitting each exam again to renew of course, and there's a new scheme to 'maintain' various certs via AWS Skill Builder which can extend them by one year rather than three.

20 Jul 2026 8:52pm GMT