Archive for sunset

deadend of the day [no filter]

Posted in pictures, Travel with tags , , , , , , , , , , on September 11, 2020 by xi'an

walk at dusk [jatp]

Posted in Statistics with tags , , , , , , , , , , , on August 24, 2020 by xi'an

Metropolis in 95 characters

Posted in pictures, R, Statistics, Travel with tags , , , , , , , , on January 2, 2020 by xi'an

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 walk with scale one as proposal. (Inspired from a X validated question.)

m<-function(T,y=rnorm(1))ifelse(rep(T>1,T),
  c(y*{f({z<-m(T-1)}[1])-f(y+z[1])<rexp(1)}+z[1],z),y)

The function is definitely not optimal, crashes for values of T larger than 580 (unless one modifies the stack size), and operates the most basic version of a Metropolis-Hastings algorithm. But as a codegolf challenge (on a late plane ride), this was a fun exercise.

green sunset [jatp]

Posted in pictures with tags , , , , , , , , , on June 17, 2019 by xi'an

Fondamenta dei Ormesini [snapshot]

Posted in pictures, Travel with tags , , , , , , , on June 2, 2019 by xi'an