Archive for Oliver Twist

more, please!

Posted in Books, Kids, R, Statistics with tags , , , , on February 26, 2021 by xi'an

As The Riddler proposed for several weeks in a row a CrossProduct™ puzzle where 3 x n one-digit integers have to be deduced from their rowwise and columnwise products, I attempted writing an R solver by applying a few basic rules repeatedly, which worked for the first two puzzles, if not for the earlier one I solved by paper & pen (mostly) a few weeks ago, and again worked for the final one. The rules I used were to spot unique entries, forced entries by saturation, and forced digits (from the prime factor decomposition) again by saturation. Any further rule to add to the solver? (The R code is currently rather ugly!) Please, some more!

more random than random!

Posted in Books, Kids, pictures, Statistics with tags , , , , , , on December 8, 2017 by xi'an

A revealing question on X validated the past week was asking for a random generator that is “more random” than the outcome of a specific random generator, à la Oliver Twist:The question is revealing of a quite common misunderstanding of the nature of random variables (as deterministic measurable transforms of a fundamental alea) and of their maybe paradoxical ability to enjoy stability or predictable properties. And much less that it relates to the long-lasting debate about the very [elusive] nature of randomness. The title of the question is equally striking: “Random numbers without pre-specified distribution” which could be given some modicum of meaning in a non-parametric setting, still depending on the choices made at the different levels of the model…