1691 search results for "time series"

Using bigmemory for a distance matrix

April 7, 2012
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Using bigmemory for a distance matrix

The process of working on metadata and temperature series gives rise to several situations where I need to calculate the distance from every station to every other station. With a small number of stations this can be done easily on the fly with the result stored in a matrix. The matrix has rows and columns

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R-Bloggers’ Web-Presence

April 6, 2012
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We love them, we hate them: RANKINGS!Rankings are an inevitable tool to keep the human rat race going. In this regard I'll pick up my last two posts (HERE & HERE) and have some fun with it by using it to analyse R-Bloggers' web presence. I will use...

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Resampling Hierarchically Structured Data Recursively

April 4, 2012
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Resampling Hierarchically Structured Data Recursively

That's a mouthful! I presented this topic to a group of Vandy statisticians a few days ago. My notes (essentially reproduced in this post) are recorded at the Dept. of Biostatistics wiki: HowToBootstrapCorrelatedData. The presentation covers some bootstrap strategies for hierarchically structured (correlated) data, but focuses on the multi-stage bootstrap; an extension of that described

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Web-Scraping in R

April 2, 2012
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Web-Scraping in R

Web-scraping, or web-crawling, sounds like a seedy activity worthy of an Interpol investigative department. The reality, however, is far less nefarious. Web-scraping is any procedure by which someone extracts data from the internet. Given that it’s possible to get the internet on computers these days; web-scrapping opens an array of interesting possibilities to social-science researchers

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Introduction to ORE Embedded R Script Execution

April 2, 2012
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Introduction to ORE Embedded R Script Execution

This Oracle R Enterprise (ORE) tutorial, on embedded R execution, is the third in a series to help users get started using ORE. See these links for the first tutorial on the transparency layer and second tutorial on the statistics engine. Oracle R Enterprise is a component in the Oracle Advanced Analytics Option of Oracle Database Enterprise...

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Surveys, Assumptions, and the Need for Data Collection Alternatives

April 2, 2012
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Surveys, Assumptions, and the Need for Data Collection Alternatives

This is a long post. My previous posts have mostly been about my thoughts on various research subjects. This one reports an actual analysis. If you don’t want to read the whole thing, here are the highlights: We really need to stop using surveys so much. If we have to use surveys, it’s probably best

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R 2.15.0 is released

March 30, 2012
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R 2.15.0 is released

Bellow is the announcement made by Peter Dalgaard: The build system rolled up R-2.15.0.tar.gz (codename “Easter Beagle”) at 9:00 this morning. This is the first release of the 2.15 series and contains several new features and changes; see the list below for details. You can get the source code from http://cran.r-project.org/src/base/R-2/R-2.15.0.tar.gz or wait for it to be mirrored at...

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Bootstrap example

March 30, 2012
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Bootstrap example

Bootstrap your way into robust inference. Wow, that was fun to write.. Introduction Say you made a simple regression, now you have your . You wish to know if it is significantly different from (say) zero. In general, people look … Continue reading →

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Visualizing left-right government positions

March 19, 2012
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Visualizing left-right government positions

How does the political landscape of Europe change over time? One way to approach this question is to map the socio-economic left-right positions of the governments in power. So let’s plot the changing ideological  positions of the governments using data … Continue reading →

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Independent measures (between-subjects) ANOVA and displaying confidence intervals for differences in means

March 18, 2012
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Independent measures (between-subjects) ANOVA and displaying confidence intervals for differences in means

In Chapter 2 (Confidence Intervals) of Serious stats I consider the problem of displaying confidence intervals (CIs) of a set of means (which I illustrate with the simple case of two independent means). Later, in Chapter 16 (Repeated Measures ANOVA), I consider the trickier problem of displaying of two or more means from paired or

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