5236 search results for "git"

Summarising multivariate palaeoenvironmental data

January 9, 2014
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Summarising multivariate palaeoenvironmental data

The horseshoe effect is a well known and discussed issue with principal component analysis (PCA) (e.g. Goodall 1954; Swan 1970; Noy-Meir & Austin 1970). Similar geometric artefacts also affect correspondence analysis (CA). In part 1 of this series I looked at the implications of these “artefacts” for the recovery of temporal or single dominant gradients from multivariate palaeoecological data....

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USA Drought of 2013: Analysis of High-resolution Rainfall Data Using R

January 8, 2014
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USA Drought of 2013: Analysis of High-resolution Rainfall Data Using R

The ongoing drought in California and other parts of Southwestern United States has been reported extensively by newspapers and government sites.Although rainfall deficit is technically meteorological drought, and drought could be of several other...

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Fast-track publishing using knitr: exporting images for sharing and press (part III)

January 7, 2014
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Fast-track publishing using knitr: exporting images for sharing and press (part III)

(This article was first published on G-Forge » R, and kindly contributed to R-bloggers) Images can be a powerful medium if used right. The image is CC by alemdag. Fast-track publishing using knitr is a short series on how I use knitr to speedup publishing in my research. This is the third article in the series devoted to plots....

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R vs Stata: Importing and Saving Datasets

January 6, 2014
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R vs Stata: Importing and Saving Datasets

Today, I got a license of the new Stata/MP 13 (dual core), so I decided to make some succinct comparisons with R (Rstudio). Much more tests will come in the following weeks, but today I focused only on the basics: processing text files. Essentially, reading and writing raw datasets. The results I obtained, surprised me—I've

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The Rain Project: An R-based Open Source Analysis of Publicly Available Rainfall Data

January 6, 2014
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Rainfall data used by researchers in academia and industry does not always come in the same format. Data is often in atypical formats and in extremely large number of files and there is not always guidance on how to obtain, process and visualize the da...

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analyze the national immunization survey (nis) with r

January 6, 2014
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for twenty years now, the centers for disease control and prevention (cdc) has been random-digit-dialing american households to ask parents which vaccinations their little tykes have received.  and since vaccination history might not be at the for...

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Analyse your bank statements using R

January 4, 2014
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Analyse your bank statements using R

Online banking has made reviewing statements and transferring money more convenient than ever before, but most still rely on external methods for looking at their personal finances. However, many banks will happily give you access to long-term transaction logs, and … Continue reading →

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Relenium, Selenium for R. A new tool for webscraping.

January 4, 2014
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Relenium, Selenium for R. A new tool for webscraping.

  Two members of the RugBcn  have developed a package for R that ease the path for webscraping . Among the current packages, we highlight the well known RCurl and XML packages. Both are enough for most situations, but they have a limitation dealing with situations where there is some javascript between the user and the information. For instance when

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Detecting a Time Series Change Point

January 4, 2014
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Detecting a Time Series Change Point

In this example we will detect the change point in a time series of counts using Bayesian methodology. A natural solution to this problem utilizes a Gibbs sampler. We’ll first implement the sampler in R naively, then create a vectorized R implementation, and lastly create an implementation of the sampler using Rcpp and RcppArmadillo. We will compare these implementations...

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The Fourier Transform, explained in one sentence

January 3, 2014
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The Fourier Transform, explained in one sentence

If, like me, you struggled to understand the Fourier Transformation when you first learned about it, this succinct one-sentence colour-coded explanation from Stuart Riffle probably comes several years too late: Stuart provides a more detailed explanation here. This is the formula for the Discrete Formula Transform, which converts sampled signals (like a digital sound recording) into the frequency domain...

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