Blog Archives

New R User Group in Montreal

March 15, 2012
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New R User Group in Montreal

The Montreal R User Group is now official. You can join the group by visiting the meetup site. The group has existed since 2010 in a narrower incarnation as the BGSA R/Stats Workshop Series. Previous workshops have featured invited facilitators on topics such as Causal Analysis, GLMs, GAMs, Multi-model inference, Phylogenetic analysis, Bayesian modeling, Meta-analysis,

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π Day Special! Estimating π using Monte Carlo

March 14, 2012
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π Day Special! Estimating π using Monte Carlo

In honour of π day (03.14 – can’t wait until 2015~) , I thought I’d share this little script I wrote a while back for an introductory lesson I gave on using Monte Carlo methods for integration. The concept is simple – we can estimate the area of an object which is inside another object

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Montreal R workshop: Plyr, reshape and other data manipulation goodies

March 8, 2012
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Montreal R workshop: Plyr, reshape and other data manipulation goodies

March 12, 2012 14h-16h N4/17 Stewart Biology Building, McGill University Étienne Low-Decarie, McGill University This workshop is organized by the BGSA and is free of charge (!), but space is limited. Register early to ensure your spot! From Étienne: Ever want to split your data according to factors, apply a function on each part and

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Montreal R workshop on Causal Inference

March 5, 2012
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Montreal R workshop on Causal Inference

Monday, March 05, 2012  14h-16h N4/17 Stewart Biology Building, McGill University Prof. Bill Shipley from Université de Sherbrooke Topics Structural equation modelling Graphical models for understanding causal analysis Testing for goodness of fit...

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Visualising the Metropolis-Hastings algorithm

February 10, 2012
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Visualising the Metropolis-Hastings algorithm

In a previous post, I demonstrated how to use my R package MHadapive to do general MCMC to estimate Bayesian models. The functions in this package are an implementation of  the Metropolis-Hastings algorithm. In this post, I want to provide an intuitive way to picture what is going on ‘under the hood’in this algorithm. The

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Gauging Interest in a Montreal R User Group

February 7, 2012
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Gauging Interest in a Montreal R User Group

Some of us over at McGill’s Biology Graduate Student Association have been developing and delivering R/Statistics workshops over the last few years. Through invited graduate students and faculty, we have tackled  everything from multi-part introductory workshops to get your feet wet, to special topics such as GLMs, GAMs, Multi-model inference, Phylogenetic analysis, Bayesian modeling, Meta-analysis,

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General Bayesian estimation using MHadaptive

February 6, 2012
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General Bayesian estimation using MHadaptive

If you can write the likelihood function for your model, MHadaptive will take care of the rest (ie. all that MCMC business). I wrote this R package to simplify the estimation of posterior distributions of arbitrary models. Here’s how it works: 1) Define your model (ie the likelihood * prior). In this example, lets build

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