Posts Tagged ‘ rstats ’

Visualising Twitter User Timeline Activity in R

February 17, 2012
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Visualising Twitter User Timeline Activity in R

I’ve largely avoided “time” in R to date, but following a chat with @mhawksey at #dev8d yesterday, I went down a rathole last night exploring a few ways of visualising a Twitter user timeline and as a result also had a quick initial play with some time handling features of R, such as timeseries...

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Generating Twitter Wordclouds in R (Prompted by an Open Learning Blogpost)

February 15, 2012
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Generating Twitter Wordclouds in R (Prompted by an Open Learning Blogpost)

A couple of weeks ago I saw a great example of an open learning blogpost from @katy_bird: Generating a word cloud (or not) from a Twitter hashtag. It described the trials and tribulations associated with trying to satisfy a request for the generation of a wordcloud based on tweets associated with a specific Twitter...

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Stupid R tricks: using outer to create many data.frame subsets

February 11, 2012
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Stupid R tricks: using outer to create many data.frame subsets

Selecting subsets of a data.frame is easy in R if you define the predicates manually. But if you need to define many conditions the standard slicing and subsetting methods are cumbersome. For this illustration I want to pick some large number of numeri...

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More Thoughts on Potential Audience Metrics for Hashtag Communities

February 10, 2012
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More Thoughts on Potential Audience Metrics for Hashtag Communities

Following on from the sketched ideas relating to estimating the Potential Audience Size for a Hashtag Community?, here are a few quick doodles around the graph representation of the tag users – followers graph that explore the extent to which we can use quite simple counts and analyses to get a feel for how...

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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....

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What is the Potential Audience Size for a Hashtag Community?

February 8, 2012
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What is the Potential Audience Size for a Hashtag Community?

What’s the potential audience size around a Twitter hashtag? Way back when, in the early days of webs stats, reported figures tended to centre around the notion of hits, the number of calls made to a server via website activity. I forget the details, but the metric was presumably generated from server logs. This...

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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,...

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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...

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Visualising Activity Around a Twitter Hashtag or Search Term Using R

February 6, 2012
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Visualising Activity Around a Twitter Hashtag or Search Term Using R

I think one of valid criticisms around a lot of the visualisations I post here and on my various #f1datajunkie blogs is that I often don’t post any explanatory context around the visualisations. This is partly a result of the way I use my blog posts in a selfish way to document the evolution...

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Monty Hall by simulation in R

February 3, 2012
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Monty Hall by simulation in R

(Almost) every introductory course in probability introduces conditional probability using the famous Monte Hall problem. In a nutshell, the problem is one of deciding on a best strategy in a simple game. In the game, the contestant is asked to select one of three doors. Behind one of the doors is a great prize...

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