Tootfinder

{testthat} is great for automatic testing. Here are some tricks for the heavy user: #rstats

Random close packing at extreme size ratios with an Adam-based inflation protocol
Kenneth Desmond
https://arxiv.org/abs/2608.12235 https://arxiv.org/pdf/2608.12235 https://arxiv.org/html/2608.12235
arXiv:2608.12235v1 Announce Type: new
Abstract: We present \texttt{rcpgenerator}, an openly available code for generating $d$-dimensional dense, disordered, non-overlapping close packings from an arbitrary prescribed list of particle diameters. The method adapts the Clarke--Wiley inflation protocol, but instead uses the Adam optimizer to relax the particle configuration. Typically, particle coordinates are advanced with a single, global step size, which must shrink as the size ratio $S\equiv D_{\max}/D_{\min}$ grows, generally stalling the optimization. Adam instead gives each coordinate its own adaptive step size, stabilizing the optimization time across a broader range of $S$. We demonstrate this in three-dimensional periodic tests that reach $S\sim5\times10^{5}$ for a continuous lognormal distribution ($N\sim10^{6}$ diameters) and particle numbers up to $N\approx5.6\times10^{6}$ for power-law distributions, with the densest packings reaching $\phi\simeq0.87$, each completed in minutes to hours on a multicore machine. Across truncated-lognormal, truncated-power-law, and Weibull distributions, the resulting $\phi$ reproduces trends such as the locations of peaks and knees with distribution shape and $S$ found in prior numerical results and in the parameter-free Farr--Groot prediction, with a remaining offset typically $0.005$--$0.01$. Additionally, results are commensurate with multimodal packing densities measured in vibrated-bed experiments. The code and the complete per-case census behind every figure are released with the paper.
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heise | Rundum beeindruckend: Vier 360-Grad-Kameras im Test
Actioncams mit zwei Objektiven öffnen die Türe für Filmtricks, die mit einzelnen Linsen nicht möglich sind. Wir haben vier 8K-fähige 360-Grad-Kameras getestet.

Rundum beeindruckend: Vier 360-Grad-Kameras im Test
Actioncams mit zwei Objektiven öffnen die Türe für Filmtricks, die mit einzelnen Linsen nicht möglich sind. Wir haben vier 8K-fähige 360-Grad-Kameras getestet.

Price Responses of Rwandan Tungsten Exports under Conflict Minerals Regulation
Haruka Nagamori, Kazuhiko Nishimura
https://arxiv.org/abs/2608.08690 https://arxiv.org/pdf/2608.08690 https://arxiv.org/html/2608.08690
arXiv:2608.08690v1 Announce Type: new
Abstract: Section 1502 of the Dodd--Frank Act, enacted in 2010, requires U.S.-listed companies using tin, tantalum, tungsten, and gold (3TG) from the Democratic Republic of the Congo and adjoining countries to disclose information on the minerals' origins. Concerns have been raised that the regulation may have induced a de facto embargo through avoidance of sourcing from the covered region. However, how the price responsiveness of mineral exports evolved under changing institutional and market conditions remains insufficiently understood. Since tungsten production in the covered region is concentrated almost entirely in Rwanda, this study examines the price responsiveness of Rwandan tungsten exports from January 2009 to December 2023.
Because missing export quantity data prevent continuous observation of export unit values, we apply the identification approach of Nakano and Nishimura (2025), combining monthly mirror trade data from UN Comtrade with exchange rates and a world average price. An importer fixed-effects model is estimated using export value as the dependent variable, with the sample divided into four periods according to changes in the institutional and market environment.
The results reveal substantial temporal variation in price responsiveness. A statistically significant negative price response is observed in Period 1 ($\eta=-20.814$, $p<0.01$), disappears in Period 2 ($\eta=1.814$, $p>0.10$), reappears in Period 3 ($\eta=-5.277$, $p<0.01$), and disappears again in Period 4 ($\eta=0.440$, $p>0.10$). Coefficient-difference tests confirm significant changes between Periods 1 and 2 ($p=0.0021$) and between Periods 3 and 4 ($p=0.0006$). These findings suggest that the price responsiveness of Rwandan tungsten exports varied substantially over time rather than following a uniform trajectory after the regulation.
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Zero days since I've discovered a random #CPython bug that triggers in very specific circumstances and I don't really have time to report it, nor can expect anyone to do it for me.
This time it's a test failure and refcounts being broken while running fastjsonschema's test suite on #Python 3.15 freethreading with pytest's --junit-xml option enabled 😱. And of course removing --junit-xml makes all tests pass.
EDIT: and of course I cannot reproduce outside Portage. Yet inside, it reliably crashes every single time.

"De vervoerder vergelijkt de drukte met piekbelasting bij stroomnetbeheerders. "Maar als een klein percentage reizigers een minder druk alternatief kiest, hoeven reizigers veel minder vaak te staan in de trein", zegt Tijmen Voet, directeur dienstregeling bij de NS."
🎯
Geef die man een baan bij een netbeheerder, of bij toezichthouder ACM!

Nét buiten de spits reizen? NS biedt goedkopere treinkaartjes aan
Met de regeling kunnen reizigers goedkopere treinkaartjes kopen voor minder drukke treinen aan de randen van de spits. De tickets moeten wel uiterlijk een dag van tevoren worden gekocht.

Offizielle AfD-Accounts: erstaunlich KI-arm. Die Fan-Community daneben: 357 Videos voller synthetischer Rentner, personifizierter Währungen und Merz-Karikaturen. Golem-Autor Oliver Jessner zeigt, wie Verlustangst zur Bildsprache wird – echte Wahlwerbung braucht es dafür offenbar kaum noch, das erledigt die Fan-Szene ganz freiwillig. #AfD

Sharp Minimax Theory for Randomized Experiments
Timothy Sudijono, Edgar Dobriban, Eric Tchetgen Tchetgen
https://arxiv.org/abs/2608.13822 https://arxiv.org/pdf/2608.13822 https://arxiv.org/html/2608.13822
arXiv:2608.13822v1 Announce Type: new
Abstract: We study minimax-optimal designs and estimators for estimating the sample average treatment effect in finite population randomized experiments, where both design and estimator are unrestricted. For binary potential outcomes, we show this minimax risk is equivalent to the minimax risk $\rho_n^*$ of an estimation problem with $2$ unknown parameters. We leverage this reduction to establish a second-order risk expansion $\rho_n^* = n^{-1} - Cn^{-4/3} o_n(n^{-4/3})$ for an explicit constant $C$ related to the Airy function. The minimax risk is attained by Bernoulli randomization with a nonlinear shrinkage estimator. Our results show that standard procedures such as complete randomization with difference in means are only minimax optimal up to first order in $n.$ We derive further results on admissibility of these procedures and discuss the practical implications of our results.
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Every week, Metacurity offers our readers a rundown of the top infosec-related long reads we couldn't properly address in the daily crush of news.
This week's selection covers,
--Zuckerberg gives risky AI agent the green light,
--TikTok’s ByteDance ties test US data safeguards,
--China’s AI expansion defies a central kill switch,
--AI agents erode the human oversight they need,
--Ukraine’s Cyber Corps shows ties to military intelligence
https://www.metacurity.com/ai-without-brakes-porous-data-boundaries-and-murky-cyber-alliances-best-infosec-long-reads-10-10-26/