Monthly Archives: March 2014

analyze the european social survey (ess) with r

March 31, 2014
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with more than a decade of microdata aimed at gauging the political mood across european nations, the european social survey (ess) allows scientists like you to examine socio-demographic shifts among broad groups all the way down to pirate party (pirat...

Correlation with constraints on pairs

March 31, 2014
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$\text{cov}(X,Y)$

An interesting question was posted on http://math.stackexchange.com/726205/…: if one knows the covariances  and , is it possible to infer ? I asked myself a question close to this one a few weeks ago (that I might also relate to a question I asked a long time ago, about possible correlations between three exchange rates, on financial markets). More precisely, if one knows the...

March 31, 2014
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In the Capturing Intraday data post, I outlined steps to setup your own process to capture Intraday data. But what do you do if you missed some data points due for example internet being down or due to power outage your server was re-started. To fill up the gaps in the Intraday data, you could

Five Reasons to Teach Elementary Statistics With R: #1

March 31, 2014
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Introduction Reason #1: Package mosaic Keeping Simple Things Simple Flow-Control for the Masses There is Much More References Introduction This is is first in a projected five-part series of posts aimed at colleagues who teach...

Five Reasons to Teach Elementary Statistics With R: #1

March 31, 2014
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Introduction Reason #1: Package mosaic Keeping Simple Things Simple Flow-Control for the Masses There is Much More References Introduction This is is first in a projected five-part series of posts aimed at colleagues who teach...

Using iterators for sparse vectors and matrices

March 31, 2014
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Iterating over a sparse vector Consider the following vector: idx1 <- c(2L, 0L, 4L, 0L, 7L)A sparse representation of this vector will tell that at entries 1,3,5 (or at entries 0,2,4 if we are 0-based) we will find the values 2,4,7. Using Eigen via RcppEigen we can obtain the coercion with .sparseView(). We can iterate over all elements (including the zeros) in a sparse vector...

Using iterators for sparse vectors and matrices

March 31, 2014
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Iterating over a sparse vector Consider the following vector: idx1 <- c(2L, 0L, 4L, 0L, 7L) A sparse representation of this vector will tell that at entries 1,3,5 (or at entries 0,2,4 if we are 0-based) we will find the values 2,4,7. Using Eigen via RcppEigen we can obtain the coercion with .sparseView(). We can iterate over all elements (including the zeros) in a sparse vector...

Predictive analysis in ecommerce

March 31, 2014
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Welcome to the blog post! We all know the predictive analysis is very hot topic now days. Everyone is looking for how the power of predictive analysis can be used in their business and get their business questions solved.  Recently, I was doing study on the predictive analysis in ecommerce. I found many interesting things The post Predictive...

April Fools’ Day: The 7 Funniest Data Cartoons

March 31, 2014
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To give this years April Fools’ day a more analytical touch, we decided last week do a little poll on internet cartoons. We asked our friends and colleagues to select their favourite data related cartoon on the web, and organized a voting session to construct a top 5 list. (You can always share your own

Process and observation uncertainty explained with R

March 31, 2014
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$Process and observation uncertainty explained with R$

Once up on a time I had grand ambitions of writing blog posts outlining all of the examples in the Ecological Detective.1 A few years ago I participated in a graduate seminar series where we went through many of the examples in this book. I am not a population biologist by trade but many of