4342 search results for "git"

Modelling memory and news trajectories

February 6, 2013
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Modelling memory and news trajectories

Modelling memory In the text below I present two models I've made to quantify and visualise the diverging trajectories of memory and news events, and conclude that linear regression may be used to test which model best describes the story. First, though, I contextualise this with an illustration from the...

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Make building R packages easier with devtools

February 6, 2013
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If you're writing any significant amount of R code, you might want to start think about bundling it up into packages. An R package combines functions, data, documentation and unit tests, and is a convenient and reliable system to manage and version collections of R content that could otherwise become unwieldy. And if you want to share your code...

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A book about Rcpp

February 5, 2013
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Some little birds had already been whispering about it, but I didn't want to jinx it and told myself I would wait with an announcement until the booksellers have (at least) placeholder pages. And as I learned from Duncan Murdoch via email earlier toda...

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Collinearity and stepwise VIF selection

February 5, 2013
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Collinearity and stepwise VIF selection

Collinearity, or excessive correlation among explanatory variables, can complicate or prevent the identification of an optimal set of explanatory variables for a statistical model. For example, forward or backward selection of variables could produce inconsistent results, variance partitioning analyses may be unable to identify unique sources of variation, or parameter estimates may include substantial amounts

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Visualizing networks in R: arc diagrams and hive plots

February 4, 2013
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Visualizing networks in R: arc diagrams and hive plots

Arc diagrams are an alternate way of representing two-dimensional graphs. Rather than scattering the nodes across the page connected by straight edges, you can instead arrange the nodes along a one-dimensional axis, and replace the straight edges with arcs between the nodes. While an arc diagram might not give as good a sense of the connections between the nodes...

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analyze the survey of income and program participation (sipp) with r

February 4, 2013
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if the census bureau's budget was gutted and only one complex sample survey survived, pray it's the survey of income and program participation (sipp).  it's giant.  it's rich with variables.  it's monthly.  it follows households over three, four, now five year panels.  the congressional budget office uses it for their health insurance simulation.  analysts read that sipp has...

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Data Visualization for Education

February 3, 2013
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Recently I was invited to give a talk to two cohorts of Strategic Data Project fellows. I was asked to speak about using data visualization to help inform decision-making of policy makers. At the same time, the group had a lot of variation in their int...

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Japanese Government Bonds (JGB) Total Return Series

February 3, 2013
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Japanese Government Bonds (JGB) Total Return Series

In a follow up to Yen and JGBs Short-Term vs Long Term and a series of posts on Japan, I thought the Bloomberg article "Japan Pension Fund’s Bonds Too Many If Abe Succeeds, Mitani Says" was particularly interesting.  It is difficult to find a to...

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An Example of Seasonality Analysis

February 3, 2013
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An Example of Seasonality Analysis

Today, I want to demonstrate how easy it is to create a seasonality analysis study and produce a sample summary report. As an example study, I will use S&P Annual Performance After a Big January post by Avondale Asset Management. The first step is to load historical prices and find Big Januaries. All the hard

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The Rcpp Gallery and my Seinfeld Streak

February 3, 2013
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A good three weeks ago, we introduced the Rcpp Gallery. While this is a joint effort by several of us on the Rcpp team, the backend was conceived and implemented entirely by JJ who also bootstrapped it with same first content, drawing on posts by Ha...

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