# Posts Tagged ‘ probability ’

## Generating a Markov chain vs. computing the transition matrix

May 23, 2013
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$h\times h$

A couple of days ago, we had a quick chat on Karl Broman‘s blog, about snakes and ladders (see http://kbroman.wordpress.com/…) with Karl and Corey (see http://bayesianbiologist.com/….), and the use of Markov Chain. I do believe that this application is truly awesome: the example is understandable by anyone, and computations (almost any kind, from what we’ve tried) are easy to perform. At the same time, some French students asked me specific details regarding…

## What is probabilistic truth?

May 18, 2013
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I am currently working on a validation metric for binary prediction models. That is, models which make predictions about outcomes that can take on either of two possible states (eg Dead/not dead, heads/tails, cat in picture/no cat in picture, etc.) The most commonly used metric for this class of models is AUC, which assesses the […]

## CAISN

May 7, 2013
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Reblogged from Zero to R Hero: Canadian Aquatic Invasive Species Networks Annual General Meeting in Kananaskis, Alberta. May 03, 3:25-5:30. This 2-hour workshop will focus on how and why we do numerical simulation in R. Time permitting, we will also look at how to build and fit likelihood based statistical models. We ask that you bring your […]

## Bayesian and Frequentist Approaches: Ask the Right Question

May 6, 2013
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It occurred to us recently that we don’t have any articles about Bayesian approaches to statistics here. I’m not going to get into the “Bayesian versus Frequentist” war; in my opinion, which style of approach to use is less about philosophy, and more about figuring out the best way to answer a question. Once you [...] Related posts: Statistics to English Translation, Part 2a: ’Significant’ Doesn’t Always Mean ’Important’ Worry…

## La belle-mère et la bataille

May 5, 2013
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$k$

Ce soir, les enfants voulaient lancer une partie de bataille dix minutes avant de souper. Devant mon peu d’enthousiasme (on ne sait jamais trop quand ce genre de parties finissent), ma belle-mère a suggéré qu’au lieu de jouer à deux (comme le voulaient les deux grands), on devrait jouer à quatre, et comme ça, ça irait plus vite. Et si ma belle-mère avait raison ? et si elle avait tort…

## In three months, I’ll be in Vegas (trying to win against the house)

April 21, 2013
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In fact, I’m going there with my family and some friends, including two probabilists (I mean professionals, I am merely an amateur), with this incredible challenge: will I be able to convince  probabilists to go to play at the Casino? Actually, I also want to study them carefully, to understand how we should play optimally. For example, I hope I can make them play the roulette. Roulette is simple. With…

## Simulating the Gambler’s Ruin

April 15, 2013
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The gambler’s ruin problem is one where a player has a probability p of winning  and probability q of losing. For example let’s take a skill game where the player x can beat player y with probability 0.6 by getting closer to a target. The game play begins with player x being allotted 5 points and player y [...]

## Mathematical abstraction and the robustness to assumptions

April 13, 2013
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I’ve been showing my new favourite toys to just about anyone foolish enough to actually engage me in conversation. I described how my shiny new set of non-transitive dice work here, complete with a map showing all the relevant probabilities. All was neat and tidy and wonderful until fellow ecologist, Aaron Ball, tried to burst [...]

## Mathematical abstraction and the robustness to assumptions

April 13, 2013
By

I’ve been showing my new favourite toys to just about anyone foolish enough to actually engage me in conversation. I described how my shiny new set of non-transitive dice work here, complete with a map showing all the relevant probabilities. All was neat and tidy and wonderful until fellow ecologist, Aaron Ball, tried to burst […]

## Dirichlet Process, Infinite Mixture Models, and Clustering

April 7, 2013
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The Dirichlet process provides a very interesting approach to understand group assignments and models for clustering effects.   Often time we encounter the k-means approach.  However, it is necessary to have a fixed number of clusters.  Often we encounter situations where we don’t know how many fixed clusters we need.  Suppose we’re trying to identify [...]