3013 search results for "GIS"

A function for comparing groups on a set of variables

May 16, 2013
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I'm often in the position of needing to compare groups of either items or participants on some set of variables. For example, I might want to compare recognition of words that differ on some measure of lexical neighborhood density but are matched on wo...

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Even More JGB Yield Charts with R lattice

May 15, 2013
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Even More JGB Yield Charts with R lattice

See the last post for all the details. I just could not help creating a couple more. Variations on Favorite Plot - Time Series Line of JGB Yields by Maturity p2 <- xyplot(value ~ date | indexname, data = jgb.melt, type = "l", layout = c(length(unique(jgb.melt$indexname)), ...

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Automated Archival and Visual Analysis of Tweets Mentioning #bog13, Bioinformatics, #rstats, and Others

May 15, 2013
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Automated Archival and Visual Analysis of Tweets Mentioning #bog13, Bioinformatics, #rstats, and Others

Automatically Archiving Twitter ResultsEver since Twitter gamed its own API and killed off great services like IFTTT triggers, I've been looking for a way to automatically archive tweets containing certain search terms of interest to me. Twitter's buil...

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Japan – JGB Yields–More Lattice Charts

May 15, 2013
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Japan – JGB Yields–More Lattice Charts

This blog is littered with posts about Japan. In one sentence, I think Japan presents opportunity and is a very interesting real-time test of much of my macro thinking. Proper visualization is absolutely essential for me to understand all of the dynami...

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Claims Inflation – a known unknown

May 14, 2013
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Over the last year I worked with two colleagues of mine on the subject of inflation and claims inflation in particular. I didn't expect it to be such a challenging topic, but we ended up with more questions than answers. The key question and biggest ch...

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Integration take two – Shiny application

May 13, 2013
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Integration take two – Shiny application

My last post discussed a technique for integrating functions in R using a Monte Carlo or randomization approach. The mc.int function (available here) estimated the area underneath a curve by multiplying the proportion of random points below the curve by the total area covered by points within the interval: The estimated integration (bottom plot) is

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Using C libraries in R with rdyncall

May 12, 2013
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Using C libraries in R with rdyncall

One reason I like using R for data analysis is that R has a great collection of packages that let you easily apply state-of-the-art methods to your problems. But once in a while you find a library that you would like to use that does not have a R wrapper, yet. While the great Rcpp

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A new package : Quandl

May 12, 2013
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A new package : Quandl

Quandl is a new database management tool which seeks to become the place to find datasets. That is, each unique indicator is considered an independent data set. This helps them to seem to have a ginormous quantity of data sets. Source : Blog Econo...

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Reproducibility and randomness

May 11, 2013
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Reproducibility and randomness

With Stéphane Tufféry, we were working this week on a chapter of a book, entitled Statistical Learning in Actuarial Science. The chapter should be based on R functions, and we wanted to reproduce some outputs he previously obtained with SAS. The good thing is that even complex functions (logistic regression, regression trees, etc) produce the same kind of outputs....

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Veterinary Epidemiologic Research: Count and Rate Data – Poisson Regression and Risk Ratios

May 10, 2013
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Veterinary Epidemiologic Research: Count and Rate Data – Poisson Regression and Risk Ratios

As noted on paragraph 18.4.1 of the book Veterinary Epidemiologic Research, logistic regression is widely used for binary data, with the estimates reported as odds ratios (OR). If it’s appropriate for case-control studies, risk ratios (RR) are preferred for cohort studies as RR provides estimates of probabilities directly. Moreover, it is often forgotten the assumption

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