Archive for xkcd
analyse des données
Posted in Books, Kids with tags analyse des données, courses, ENSAE, memorabilia, teaching, xkcd on June 24, 2021 by xi'an
meandering
Posted in Books, Kids, R, Statistics with tags arithmetic mean, composition, geometric mean, harmonic mean, median, Pythagorean means, random forest, xkcd on March 12, 2021 by xi'an
A bit of a misunderstanding from Randall Munroe and then some: the function F returns a triplet, hence G should return a triplet as well. Even if the limit does return three identical values. And he should have also included the (infamous) harmonic mean! And the subtext (behind the picture) mentions random forest statistics, using every mean one can think of and dropping those that are doing worse, while here all solutions return the same value, hence do not directly discriminate between the averages (and there is no objective function to create the nodes in the trees, &tc.).
Here is a test R code including the harmonic mean:
xkcd=function(x)c(mean(x),exp(mean(log(x))),median(x),1/mean(1/x)) xxxkcd=function(x,N=10)ifelse(rep(N==1,4),xkcd(x),xxxkcd(xkcd(x),N-1)) xxxkcd(rexp(11)) [1] 1.018197 1.018197 1.018197 1.018197
use data that does not need statistics
Posted in Books, Kids, Statistics with tags COVID, pandemics, placebo effect, vaccine, xkcd on March 2, 2021 by xi'an
missing dimensions
Posted in Statistics with tags 12 Angry Men, data graphics, data visualisation, dimension reduction, Edward Tufte, J.R. Tolkien, Lord of the Rings, Minard, Napoléon Bonaparte, Russian campaign, Russian winter, Sidney Lumet, Star Wars, xkcd on February 14, 2021 by xi'an
compression artifacts
Posted in Books, Kids, Travel with tags because it's Friday, comics, solar system, space, space exploration, video compresion, Voyager, xkcd on January 22, 2021 by xi'an
