Monthly Archives: July 2012

Review: Kölner R Meeting 6 July 2012

July 10, 2012
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Review: Kölner R Meeting 6 July 2012

The second Cologne R user meeting took place last Friday, 6 July 2012, at the Institute of Sociology. Thanks to Bernd Weiß, who provided the meeting room, we didn't have to worry about the infrastructure, like we did at our first gathering. Again, we ...

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Project Euler — problem 13

July 9, 2012
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The 13th in Project Euler is one big number problem: Work out the first ten digits of the sum of the following one-hundred 50-digit numbers. Obviously, there are some limits in machine representation of numbers. In R, 2^(-1074) is the smallest … Continue reading →

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Optimization Functions in Julia

July 9, 2012
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Optimization Functions in Julia

Over the last few weeks, I’ve made a concerted effort to develop a basic suite of optimization algorithms for Julia so that Matlab programmers used to using fminunc() and R programmers used to using optim() can start to transition code over to Julia that requires access to simple optimization algorithms like L-BFGS and the Nelder-Mead

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Preview of functional programming syntax for futile.paradigm 2.1

July 9, 2012
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Preview of functional programming syntax for futile.paradigm 2.1

I’m developing a streamlined syntax for the next release of futile.paradigm. While this version is backwards compatible, it introduces a …Continue reading »

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A gWidgets GUI for climate data

July 9, 2012
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A gWidgets GUI for climate data

If you haven’t worked with the gWidgets package it’s worth some time exploring it which is what I’ve been doing for a little paleo project I’ve been working on. After struggling with the few demos and tutorials I could find I went ahead and bought the book: Programming Graphical User Interfaces in R. Luckily the

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introduction to R: learning by doing (part 1)

July 9, 2012
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introduction to R: learning by doing (part 1)

Geography is often about statistics as it is the basis for fast exchange of information: providing a mean and standard deviation to the audience is often much easier then showing raw data: Learning a script language for this purpose can be a hard-ass work. But I think it is more often a need of practice.

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Fumblings with Ranked Likert Scale Data in R

July 9, 2012
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Fumblings with Ranked Likert Scale Data in R

The code is horrible and the visualisations quite possibly misleading, but I’m dead tired and there are a couple of tricks in the following R code that I want to remember, so here’s a contrived bit of fumbling with some data of the form: enjoyCompany tooMuchFamily 1 strongly agree strongly disagree 2 strongly agree strongly

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A Napa Valley wine tasting map, made with R and ggmap

July 9, 2012
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A Napa Valley wine tasting map, made with R and ggmap

R has had a maps package available since the very early days. It's great for simple geographic maps, but the political boundaries can be out of date. For more detailed maps, you can also download shape files and use the sp package to draw borders directly. But for accurate and attractive maps of countries, roads and satellite imagery, nothing...

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Map biodiversity records with rgbif, maps and ggplot2 packages in R

July 9, 2012
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Map biodiversity records with rgbif, maps and ggplot2 packages in R

Global Biodiversity Information Facility or GBIF is an international consortium working towards making Biodiversity information available through single portal to everyone.  GBIF with its partners are working towards mobilizing data, developing data and metadata standards, developing distributed database system and making the data accessible through APIs. At this point this largest single window data source covering wide spectrum of taxa and

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Example 9.37: (Mis)behavior of binomial confidence intervals

July 9, 2012
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Example 9.37: (Mis)behavior of binomial confidence intervals

While traditional statistics courses teach students to calculate intervals and test for binomial proportions using a normal or t approximation, this method does not always work well. Agresti and Coull ("Approximate is better than "exact' for interval estimation of binomial proportions". The American Statistician, 1998; 52:119-126) demonstrated this and reintroduced an...

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