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!
Archive for Oliver Twist
more, please!
Posted in Books, Kids, R, Statistics with tags Charles Dickens, mathematical puzzle, Oliver Twist, R, The Riddler on February 26, 2021 by xi'anmore random than random!
Posted in Books, Kids, pictures, Statistics with tags Charles Dickens, cross validated, Oliver Twist, random number generator, random variates, randomness, xkcd on December 8, 2017 by xi'anA 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…