Archive for British Columbia

Longhand [Pinot Grigio]

Posted in Statistics with tags , , , , , on January 20, 2019 by xi'an

function junction NPA

Posted in Mountains, pictures, Travel, Wines with tags , , , , , on November 20, 2018 by xi'an

the invasion of the American cheeses

Posted in Travel, Wines with tags , , , , , , , , on October 15, 2018 by xi'an

Part of the new Nafta agreement between the USA and its neighbours, Canada and Mexico, is lifting restrictions on the export of American cheeses to these countries. Having tasted high quality cheeses from Québec on my last visit to Montréal, and having yet to find similar performances in a US cheese, I looked at the list of cheese involved in the agreement, only to discover a collection of European cheese that should be protected by AOC rules under EU regulations (and only attributed to cheeses produced in the original regions):

Brie [de Meaux or de Melun?]
Burrata [di Andria?]
Camembert [missing the de Normandie to be AOC]
Coulommiers [actually not AOC!]
Emmenthal [which should be AOC Emmentaler Switzerland!]
Pecorino [all five Italian varieties being PDO]
Provolone [both Italian versions being PDO]

Plus another imposition that British Columbia wines be no longer segregated from US wines in British Columbia! Which sounds somewhat absurd if wine like those from (BC) Okanagan Valley or (Washington) Walla Walla is to be enjoyed with some more subtlety than diet cokeOwning a winery apparently does not necessarily require such subtlety!

two positions at UBC

Posted in pictures, Statistics, Travel, University life with tags , , , , , , , on September 12, 2018 by xi'an

Just to repost an announcement that the Department of Statistics at the University of British Columbia in Vancouver, BC, invites applications from outstanding new investigators for two tenure-track position at the rank of Assistant Professor. Deadline for application is October 17. More information is available there. (The above sculpture is the iconic Raven and the First Men by Billy Reid.)

riddles on a line [#2]

Posted in Books, Kids, R with tags , , , , , , , on September 11, 2018 by xi'an

A second Riddle(r), with a puzzle related with the integer set Ð={,12,3,…,N}, in that it summarises as

Given a random walk on Ð, starting at the middle N/2, with both end states being absorbing states, and a uniform random move left or right of the current value to the (integer) middle of the corresponding (left or right) integer interval, what is the average time to one absorbing state as a function of N?

Once the Markov transition matrix M associated with this random walk is defined, the probability of reaching an absorbing state in t steps can be derived from the successive powers of M by looking at the difference between the probabilities to be (already) absorbed at both t-1 and t steps. From which the average can be derived.

avexit <- function(N=100){
 #transition matrix M for the walk
 #1 and N+2 are trapping states
 tranz=matrix(0,N+2,N+2)
 tranz[1,1]=tranz[N+2,N+2]=1
 for (i in 2:(N+1))
  tranz[i,i+max(trunc((N+1-i)/2),1)]=tranz[i,i-max(trunc((i-2)/2),1)]=1/2
 #probabilities of absorption
 prowin=proloz=as.vector(0)
 init=rep(0,N+2)
 init[trunc((N+1)/2)]=1 #first position
 curt=init
 while(1-prowin[length(prowin)]-proloz[length(prowin)]>1e-10){
  curt=curt%*%tranz
  prowin=c(prowin,curt[1])
  proloz=c(proloz,curt[N+2])}
 #probability of new arrival in trapping state
 probz=diff(prowin+proloz)
 return(sum((2:length(proloz))*probz))}

leading to an almost linear connection between N and expected trapping time.

the kingfisher and the heron [jatp]

Posted in Statistics with tags , , , , , , , , , , on September 8, 2018 by xi'an

going on a bear [and a whale] hunt

Posted in Mountains, pictures, Travel with tags , , , , , , , , , , , , , , on August 27, 2018 by xi'an


Among many and diverse outdoor activities during our vacations on Vancouver Island, a rather unique trip was to go kayaking near Tofino to try to watch black bears. In a group of three sea kayaks, at dusk, with a fantastic guide. Bears foraging for crabs on the shore at low tide are not unusual but, as it happened, we were quite lucky to spot five different bears over the two hours we paddle along the fjord, including a big one standing on its back legs to catch berries. From a few meters away, this was an incredible sight! [About the title: We’re going on a bear hunt is a classic of children books.]
We were less lucky when whaling out at sea, only spotting a blow on the trip, even though we spotted many seals and a few sea otters. The most exhilarating wildlife experience of the Van trip was however swimming with seals on the northern coast of the island, where on several days one or two seals came to check on me while I was swimming in the ocean in the early morning. (Managing to avoid cold shock and hypothermia by only staying less than 20 minutes in the 17⁰ water.)