3151 search results for "map"

Quoting Tukey on Visual Storytelling with Data

January 23, 2014
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Time was when I used to be a reasonably competent scholar, digging into the literature chasing down what folk actually said, and chasing forward to see whether claims had been refuted. Then I fell out of love with the academic literature – too many papers that said nothing, too many papers that contained errors, too

Hopping into R

January 22, 2014
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With the new Joyent Manta R SDK we're diving into the R community, so we're honored to be included in the R-Bloggers blog here. We hope to have more R and statistics posts there. The packages' author, Dr. Christopher Hogue has been a great addition to...

Visualizing Autoregressive Time Series

January 21, 2014
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$AR(1)$

In the MAT8181 graduate course on Time Series, we started discussing autoregressive models. Just to illustrate, here is some code to plot  – causal – process, > graphar1=function(phi){ + nf <- layout(matrix(c(1,1,1,1,2,3,4,5), 2, 4, byrow=TRUE), respect=TRUE) + e=rnorm(n) + X=rep(0,n) + for(t in 2:n) X=phi*X+e + plot(X,type="l",ylab="") + abline(h=mean(X),lwd=2,col="red") + abline(h=mean(X)+2*sd(X),lty=2,col="red") + abline(h=mean(X)-2*sd(X),lty=2,col="red") + u=seq(-1,1,by=.001) + plot(0:1,0:1,col="white",xlab="",ylab="",axes=FALSE,ylim=c(-2,2),xlim=c(-2.5,2.5)) + polygon(c(u,rev(u)),c(sqrt(1-u^2),rev(-sqrt(1-u^2))),col="light yellow")...

Fun with the Raspberry Pi

January 21, 2014
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Since Christmas I have been playing around with a Raspberry Pi. It is certainly not the fastest computer, but what a great little toy! Here are a few experiences and online resources that I found helpful. SetupInitially I connected the Raspberry Pi via HDMI to a TV; together with keyboard, mouse and an old USB Wifi adapter....

RProtoBuf 0.4.0: A whole lot of goodies and Windoze support

January 20, 2014
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A new major release 0.4.0 of RProtoBuf, is now on CRAN. RProtoBuf provides GNU R bindings for the Google Protocol Buffers ("Protobuf") data encoding library used and released by Google, and deployed as a language and operating-system agnostic proto...

Second NYC R classes(announcement and teaching experience)

January 20, 2014
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(The photo was from our first offering of R classes) We are going to offer our Data Science by R (beginner level) course again in February. The goal of this class is to get students to a point where they are self-sufficient in R, are proficient at analyzing data and can take these skills back to their full-time jobs....

Visualization Series: Using Scatterplots and Models to Understand the Diamond Market (so You Don’t Get Ripped Off)

January 19, 2014
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My last post railed against the bad visualizations that people often use to plot quantitive data by groups, and pitted pie charts, bar charts and dot plots against each other for two visualization tasks.  Dot plots came out on top. … Continue reading →

Using the plyr package

January 18, 2014
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Introduction The base R system provides lapply() and related functions, and the package plyr provides alternatives that are worth considering. It will be assumed that readers are familiar with lapply() and are willing to spend a few moments reading the plyr documentation, to see why the illustration here will use the ldply() function. The test task will be extraction of...

R Users, Meet Joyent Manta; Manta Users, Meet R

January 17, 2014
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When I joined Joyent last year, I jumped on the opportunity to make R work with Joyent Manta. If you are new to Joyent, we are the High-Performance Cloud Infrastructure Company. If you are new to data analytics, the R language is a rich open-source env...

Computing and visualizing LDA in R

January 15, 2014
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$Computing and visualizing LDA in R$

As I have described before, Linear Discriminant Analysis (LDA) can be seen from two different angles. The first classify a given sample of predictors to the class with highest posterior probability . It minimizes the total probability of misclassification. To compute it uses Bayes’ rule and assume that follows a Gaussian distribution with class-specific mean