269 search results for "PCA"

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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For descriptive statistics, values below LLOQ set to …

February 3, 2013
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For descriptive statistics, values below LLOQ set to …

That is what I read the other day. For calculation of descriptive statistics, values below the LLOQ (lower limit of quantification)  were set to.... Then I wondered, wasn't there a trick in JAGS to incorporate the presence of missing data while es...

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Rcpp reaches 100 dependents on CRAN

January 23, 2013
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With the arrival earlier today of the stochvol package onto the CRAN network for R, our Rcpp project reached a new milestone: 100 packages have either a Depends:, Imports: or LinkingTo: statement on it. The full list will always be at the bottom of ...

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Oracle R Distribution Performance Benchmark

January 18, 2013
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Oracle R Distribution Performance Benchmark

Oracle R Distribution Performance Benchmarks Oracle R Distribution provides dramatic performance gains with MKL Using the recognized R benchmark R-benchmark-25.R test script, we compared the performance of Oracle R Distribution with and with...

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Decluttering ordination plots in vegan part 2: orditorp()

January 13, 2013
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Decluttering ordination plots in vegan part 2: orditorp()

In the earlier post in this series I looked at the ordilabel() function to help tidy up ordination biplots in vegan. An alternative function vegan provides is orditorp(), the last four letters abbreviating the words text or points. That is … Continue reading →

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Decluttering ordination plots in vegan part 2: orditorp()

January 13, 2013
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Decluttering ordination plots in vegan part 2: orditorp()

In the earlier post in this series I looked at the ordilabel() function to help tidy up ordination biplots in vegan. An alternative function vegan provides is orditorp(), the last four letters abbreviating the words text or points. That is a pretty good description of what orditorp() does; it...

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Decluttering ordination plots in vegan part 1: ordilabel()

January 12, 2013
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Decluttering ordination plots in vegan part 1: ordilabel()

In an earlier post I showed how to customise ordination diagrams produced by our vegan package for R through use of colours and plotting symbols. In a series of short posts I want to cover some of the options available … Continue reading →

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Decluttering ordination plots in vegan part 1: ordilabel()

January 12, 2013
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Decluttering ordination plots in vegan part 1: ordilabel()

In an earlier post I showed how to customise ordination diagrams produced by our vegan package for R through use of colours and plotting symbols. In a series of short posts I want to cover some of the options available in vegan that can be used to help in producing better, clearer,...

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Factor Analysis of Baseball’s Hall of Fame Voters

January 9, 2013
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Factor Analysis of Baseball’s Hall of Fame Voters

Factor Analysis of Baseball's Hall of Fame VotersRecently, Nate Silver wrote a post which analyzed how voters who voted for and against Barry Bonds for Baseball's Hall of Fame differed. Not surprisingly, those who voted for Bonds were more likely to vote for other suspected steroids users (like Roger Clemens). This got...

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More Principal Components Fun

January 6, 2013
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More Principal Components Fun

Today, I want to continue with the Principal Components theme and show how the Principal Component Analysis can be used to build portfolios that are not correlated to the market. Most of the content for this post is based on the excellent article, “Using PCA for spread trading” by Jev Kuznetsov. Let’s start by loading

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