2149 search results for "twitter"

How to display scatter plot matrices with R and lattice

How to display scatter plot matrices with R and lattice

In lattice, there is a function called splom for the display of scatter plot matrices. For large datasets, the panel.hexbinplot from the hexbin package is a better option than the default panel. As an example, let’s use some meteorological data from MAPA-SIAR: library(solaR) library(hexbin) aranjuez <- readMAPA(prov=28, est=3, start='01/01/2004', end='31/12/2010') aranjuezDF <- subset(as.data.frame(getData(aranjuez)), select=c('TempMedia', 'TempMax',

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Staying up to date on R packages

March 17, 2011
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Unless you regularly use particular R packages,  it’s becomes difficult to stay on top of updates and bug fixes.  Updates usually also include significant improvements in performance.  I wrote this short snippet of code which I run about once a month to keep up on updates. This short bit of code will give you a

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Canabalt Revisited: Gamma Distributions, Multinomial Distributions and More JAGS Goodness

March 16, 2011
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Canabalt Revisited: Gamma Distributions, Multinomial Distributions and More JAGS Goodness

Introduction Neil Kodner recently got me interested again in analyzing Canabalt scores statistically by writing a great post in which he compared the average scores across iOS devices. Thankfully, Neil’s made his code and data freely available, so I’ve been revising my original analyses using his new data whenever I can find a free minute.

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Parallel computation [revised]

March 14, 2011
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Parallel computation [revised]

We have now completed our revision of the parallel computation paper and hope to send it to JCGS within a few days. As seen on the arXiv version, and given the very positive reviews we received, the changes are minor, mostly focusing on the explanation of the principle and on the argument that it comes

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Hacker News Analysis

March 13, 2011
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Hacker News Analysis

I was playing around with the Hacker News database Ronnie Roller made (thanks!), so I thought I’d post some of my findings. Activity on the Site My first question was: how has activity on the site increased over time? I … Continue reading →

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Piiikaaachuuuuuu vs. KHAAAAAN!

March 13, 2011
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Piiikaaachuuuuuu vs. KHAAAAAN!

This is a fun image I found on Neil Kodner’s blog: But I’ve never actually watched any of the Star Trek movies, so I decided to recreate the graph with Pikachu instead: Here’s a smoothed version to better compare the counts … Continue reading →

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A Kernel Density Approach to Outlier Detection

March 13, 2011
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A Kernel Density Approach to Outlier Detection

I describe a kernel density approach to outlier detection on small datasets. In particular, my model is the set of prices for a given item that can be found online. Introduction Suppose you’re searching online for the cheapest place to … Continue reading →

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Eigensheep

March 13, 2011
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Eigensheep

Aaron Koblin’s Sheep Market visualization is an awesome use of Mechanical Turk. But it’d be even more awesome if the grid were ordered, so inspired by the use of eigenfaces in facial recognition, I decided to try projecting the sheep … Continue reading →

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Counting Clusters

March 13, 2011
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Counting Clusters

Given a set of numerical datapoints, we often want to know how many clusters the datapoints form. Two practical algorithms for determining the number of clusters are the gap statistic and the prediction strength. Gap Statistic The gap statistic algorithm … Continue reading →

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Legendary Plots

March 12, 2011
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Legendary Plots

I was recently pointed in the direction of a thermal comfort model by the engineering company Arup (p27–28 of this pdf). Figure 3 at the top of p28 caught my attention. It’s mostly a nice graph; there’s not too much junk in it. One thing that struck me was that there is an awful lot

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