Monthly Archives: September 2012

BaselR meetup

September 6, 2012
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Mango Solutions host BaselR, a free, open and informal R user group for those using or interested in using R. There will be a few short R related presentations and an opportunity to meet and chat with other R users over a drink. Date: Thursday 13th September at 6.30pm. Venue : transBarent, Viaduktstrasse 3, Basel (by the train station)...

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Inference and autoregressive processes

September 6, 2012
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Inference and autoregressive processes

Consider a (stationary) autoregressive process, say of order 2, for some white noise with variance . Here is a code to generate such a process, > phi1=.5 > phi2=-.4 > sigma=1.5 > set.seed(1) > n=240 > WN=rnorm(n,sd=sigma) > ...

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Visually weighted/ Watercolor Plots, new variants: Please vote!

September 6, 2012
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Visually weighted/ Watercolor Plots, new variants: Please vote!

Update Oct-23: Added a new parameter add to the function. Now multiple groups can be plotted in a single plot (see example in my comment) As a follow-up on my R implementation of Solomon’s watercolor plots, I made some improvements to the function. I fine-tuned the graphical parameters (the median smoother line now diminishes faster

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Comparing Stan to JAGS for Bayesian Inference (Part 1?)

September 5, 2012
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Comparing Stan to JAGS for Bayesian Inference (Part 1?)

Stan is a new, open source, Bayesian inference tool. Stan is based on the the No-U-Turn sampler, a variant of Hamiltonian Monte Carlo. In order to compare Stan with JAGS, a gibbs sampler approach to Bayesian inference, I used the classic WinBUGS rats example. The rats example uses a hierarchical model to look at...

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Suicide statistics and the Christchurch earthquake

September 5, 2012
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Suicide statistics and the Christchurch earthquake

Suicide is a tragic and complex problem. This week New Zealand’s Chief Coroner released its annual statistics on suicide, which come with several tables and figures. One of those figures refers to monthly suicides in the Christchurch region (where I … Continue reading →

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K-means in images and R

K-means in images and R

In an image each pixel is a color and that color hava a RGB representation, this means each color is represented by a triplet. For example the red in this representation is (250, 0, 0), black is (0,0,0) and white is (250, 250, 250) (see here more ...

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Graphically Comparing Confidence Intervals From Different Models

September 5, 2012
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(This article was first published on Christopher Gandrud (간드루드 크리스토파), and kindly contributed to R-bloggers) To leave a comment for the author, please follow the link and comment on his blog: Christopher Gandrud (간드루드 크리스토파). R-bloggers.com offers daily e-mail updates about R news and tutorials on topics such as: visualization (ggplot2, Boxplots, maps, animation), programming (RStudio, Sweave, LaTeX, SQL,...

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A Return to Reliable R

September 5, 2012
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A Return to Reliable R

The saga with Statistica continues: Statistica kept crashing on me while doing my data processing.  One of the big problems was a wonderful bug that occurred when some of my text data variables were coded (unsurprisingly) as text!  Under this … Continue reading →

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Style your ggplot2 charts with Themes

September 5, 2012
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Style your ggplot2 charts with Themes

An update to the ggplot2 "grammar of graphics" package for R is now available on CRAN. This version introduces "Themes" for ggplot2 charts, and makes it possible to define and re-use your own preferences for title fonts and sizes, tick marks, grid color, etc. The system is heirarchically defined, so for example you can choose a font and have...

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Near-instant high quality graphs in R

September 5, 2012
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Near-instant high quality graphs in R

One of the main attractions of R (for me) is the ability to produce high quality graphics that look just the way you want them to. The basic plot functions are generally excellent for exploratory work and for getting to know your data. Most packages have additional functions for appropriate exploratory work or for summarizing

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