fidzu : debian

A new small package of mine just hit CRAN. The tl package wraps the (also very new) rspdlite package (announced last week) to offer a lightweight and consistent logging interface from both R and C++ that is also 'tiny, fast, capable' thanks to rspdlite.

The rspdlite announcement is a good place to get a first glimpse at that package; the upstream spdlite repo has all the details (for the C++ side of things). With tl we follow the same idea that our [spdl][spdl] package introduced: a simple consistent interface via just the tl:: prefix and the appropropriate logging level. In other words tl::debug("Alert -- foo is at '{}'", foo) will work from both R and C++ (given a variable foo, and in the case of C++ an extra semicolon). Just give it a try, and see how it goes. The package is still young and small.

The NEWS entry for this release is also very simple and just announces that we have a release. More details are in the ChangeLog and the GitHub repo.

Changes in version 0.0.1 (2025-06-17)

• Initial CRAN upload

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.

23 Jun 2026 1:45am GMT

The seL4 organisation on GitHub uses git-repo to manage multiple source repositories, and so there are a large number of projects to get your head around when figuring out the ecosystem.

As an experiment, I have taken the various manifest files across the org, and constructed a graph based on how frequently each pair of repositories is mentioned in a manifest together. See below:

[This may render badly when syndicated outside of my blog; and also on small screens. And probably large screens. I've attempted to make sure there's a non-JS fallback - on my site with JS enabled, if you hover over a node, it should highlight connected nodes.]

The colouring of the nodes is mostly manual; I experimented with graph clustering algorithms but have not found a satisfactory result so far. Still, some clusters are obvious:

• Kernel - the seL4 microkernel proper. This often but not always co-exists with the main cluster of core libraries, but it is pulled away slightly by the verification and microkit manifests.

• Verification - the verification repositories (l4v, HOL, graph-refine, polyml, isabelle) form a very distinct group. These are connected only to the seL4 microkernel itself, which is the only component formally verified.

• Microkit - microkit is a newer operating system framework that does not use CAmkES, so stands apart from the rest of the pack. I chose to scope this work to the seL4 org, so the LionsOS ecosystem and sDDF which are maintained by Trustworthy Systems are not shown. Also not linked is rust-sel4, because this modern world isn't using git-repo in the main to manage its repositories.

• RefOS - I'd not come across refos before, but it appears to be an example OS from 2021 built on the seL4 kernel.

It's quite hard to pull apart the CAmkES framework and the core libraries; there are definitely some which are more associated with VM management, but the overall shape of this co-occurence data is a messy ball in the middle with some outliers in orbit. One observation is that camkes is correctly identified as more peripheral than camkes-tool, which contains the actual core CAmkES code.

Reflecting on this approach, in hindsight I'm surprised that using co-occurences worked as well as it did - there was no attempt to actually inspect the code and find direct mentions of other code e.g. library header dependencies. As the newer microkit effort largely eschews git-repo, better results might be found by actually taking that more detailed approach, so that graph edges could represent real dependencies between two packages. Additionally, this could allow diving into the various libraries held in the different 'libs' repos, to get a more granular graph of relationships between them.

However, I think I spent more time on making it possible to render graphviz graphs easily on my blog than actually gaining any insight into the codebase!

21 Jun 2026 3:36pm GMT

Armadillo is a powerful and expressive C++ template library for linear algebra and scientific computing. It aims towards a good balance between speed and ease of use, has a syntax deliberately close to Matlab, and is useful for algorithm development directly in C++, or quick conversion of research code into production environments. RcppArmadillo integrates this library with the R environment and language-and is widely used by (currently) 1282 other packages on CRAN, downloaded 47.1 million times (per the partial logs from the cloud mirrors of CRAN), and the CSDA paper (preprint / vignette) by Conrad and myself has been cited 697 times according to Google Scholar.

This versions updates to the 15.4.0 upstream Armadillo release made on Thursday. We had run a complete reverse-dependency check leading up to it, asserting there were no issues with packages dependent on it. As it sometimes goes with that many packages involved, one CRAN package reported one test failure. And it turned out to be both unrelated and pre-existing. But sorting this out over one round of email delayed things by a day. And then I went cycling for a good cause so this announcement post comes a little later than usual. The package has also been updated for Debian, built for r2u, and by now also at CRAN for the different binary releases.

All changes since the last CRAN release follow.

Changes in RcppArmadillo version 15.4.0-1 (2026-06-17)

• Upgraded to Armadillo release 15.4.0 (Medium Roast Agave)

  • Added fill::nan, fill::pos_inf, fill::neg_inf as optional fill forms for the Mat class

  • Added .push_back() for appending elements to vectors

  • Faster handling of find() within .elem()

  • Faster element-wise min() and max()

  • Faster conv_to when element types of input and output objects are the same

Courtesy of my CRANberries, there is a diffstat report relative to previous release. More detailed information is on the RcppArmadillo page. Questions, comments etc should go to the rcpp-devel mailing list off the Rcpp R-Forge page.

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. You can also sponsor my Tour de Shore 2026 ride in support of the Maywood Fine Arts Center.

21 Jun 2026 2:18pm GMT