Le Monde puzzle [#1144]
The weekly puzzle from Le Monde is again using 2020 but not R! Two teams involve a prime total number m of participants, with each player getting between 0 and...continue reading.
Author: xi'an
more games of life
Another puzzle in memoriam of John Conway in The Guardian: Find the ten digit number, abcdefghij. Each of the digits is different, and a is divisible by 1 ab is...continue reading.
free Springer textbooks [incl. Bayesian essentials]
This article is originally published at https://xianblog.wordpress.com Thanks for visiting r-craft.org This article is originally published at https://xianblog.wordpress.com Please visit source website for post related comments.continue reading.
Le Monde puzzle [#1141]
The weekly puzzle from Le Monde is in honour of John Conway, who just passed away, ending up his own game of life: On an 8×8 checker-board, Alice picks n...continue reading.
simulating a sum of Uniforms
When considering the distribution of the sum (or average) of N Uniform variates, called either Irwin-Hall for the sum or Bates for the average, simulating the N uniforms then adding...continue reading.
Le Monde puzzle [#1139]
A weekly Monde current mathematical puzzle that reminded me of an earlier one (but was too lazy to check): The integer n=36 enjoys the property that all the differences between...continue reading.
random generators produce ties
“…an essential part of understanding how many ties these RNGs produce is to understand how many ties one expects in 32-bit integer arithmetic.” A sort of a birthday-problem paper for...continue reading.
Le Monde puzzle [#1133]
A weekly Monde current mathematical puzzle that reminded me of an earlier one (but was too lazy to check): If ADULE-ELUDE=POINT, was is the largest possible value of POINT? With...continue reading.
Le Monde puzzle [#1134]
A weekly Monde current mathematical puzzle on gcd’s and scm’s: If one replaces a pair (a,b) of integers with the pair (g,s) of their greatest common denominator and smallest common...continue reading.
one or two?
A superposition of two random walks from The Riddler: Starting from zero, a random walk is produced by choosing moves between ±1 and ±2 at each step. If the choice...continue reading.
chain of lynx and drove of hares
A paper (and an introduction to the paper) in Nature this week seems to have made progress on the existence of indefinite predator-prey cyles. As in the lynx/hare dataset available...continue reading.
multiplying the bars
The latest Riddler makes the remark that the expression |-1|-2|-3| has no unique meaning (and hence value) since it could be | -1x|-2|-3 | = 5 or |-1| – 2x|-3|...continue reading.
Le Monde puzzle [#1132]
A vaguely arithmetic challenge as Le weekly Monde current mathematical puzzle: Given two boxes containing x and 2N+1-x balls respectively. If one proceeds by repeatedly transferring half the balls from...continue reading.
Le Monde puzzle [#1129]
A number challenge as Le weekly Monde current mathematical puzzle: When the three consecutive numbers 110, 111 and 112, they all are multiples of the sum of their digits. Are...continue reading.
Le Monde puzzle [#1130]
A two-player game as Le weekly Monde current mathematical puzzle: Abishag and Caleb fill in alternance a row of N boxes in a row by picking one then two then...continue reading.
another easy Riddler
A quick riddle from the Riddler In a two-person game, Abigail and Zian both choose between a and z. Abigail win one point with probability .9 if they choose (a,a)...continue reading.
Le Monde puzzle [#1127]
A permutation challenge as Le weekly Monde current mathematical puzzle: When considering all games between 20 teams, of which 3 games have not yet been played, wins bring 3 points,...continue reading.
an elegant sampler
Following an X validated question on how to simulate a multinomial with fixed average, W. Huber produced a highly elegant and efficient resolution with the compact R code tabulate(sample.int((k-1)*n, s-n)...continue reading.
Le Monde puzzle [#1120]
A board game as Le weekly Monde current mathematical puzzle: 11 players in a circle and 365 tokens first owned by a single player. Players with at least two tokens...continue reading.
Metropolis in 95 characters
Here is an R function that produces a Metropolis-Hastings sample for the univariate log-target f when the later is defined outside as another function. And when using a Gaussian random...continue reading.
