# Monthly Archives: March 2013

## Benford law and lognormal distributions

March 28, 2013
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$X$

Benford’s law is nowadays extremely popular (see e.g. http://en.wikipedia.org/…). It is usually claimed that, for a given set data set, changing units does not affect the distribution of the first digit. Thus, it should be related to scale invariant distributions. Heuristically, scale (or unit) invariance means that the density of the measure  (or probability function) should be proportional to...

## Creating a Business Dashboard in R

March 28, 2013
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Business dashboards are available in many shapes and sizes. Business dashboards are useful to create an overview of key performance indicators (KPIs) important for the business strategy and/or operations. There are many flavours of dashboard frameworks and apps available, ranging in price from thousands of dollars to open-source implementations. Apparently there are four key elements to a good dashboard: Simple, communicates easily Minimum distractions…it could cause...

## Lots of data != "Big Data"

March 28, 2013
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by Joseph Rickert When talking with data scientists and analysts — who are working with large scale data analytics platforms such as Hadoop — about the best way to do some sophisticated modeling task it is not uncommon for someone to say, "We have all of the data. Why not just use it all?" This sort of comment often...

## Rencontres R, Lyon 27-28 June

March 28, 2013
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Last year, the first French-speaking R conference, “Rencontres R“  was held in Bordeaux.  The meeting was a great success, and a second one will be  held in Lyon on 27 and 28 June 2013. The abstract submission deadline of 7 … Continue reading →

## RForcecom – An R package provides the connection between R and Salesforce.com

March 28, 2013
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In this post, I’ll introduce an R package RForcecom and its usage. As you may know, R statistical computing environment is the most populous statistical computing software, and Salesforce.com is the world’s most innovative cloud-computing based SaaS (Software-as-a-Service) CRM package.…Read more ›

## Mixed model R2 (UPDATED)

March 28, 2013
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R2 is a useful tool for determining how strong the relationship between two variables is. Unfortunately, the definition of R2 for mixed effects models is difficult – do you include the random variable or just the fixed effects? Including just the fixed effects is essentially a standard linear model, while including the random effects could

## “Building ractives is so addictive it should be illegal!”

March 27, 2013
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clickme is an amazing R package. I was not sure what to expect when I first saw Nacho Caballero's announcement. I actually was both skeptical and intimidated, but neither reaction was justified. The examples prove its power, and his wiki tutorials ease...

## Moving to R 3.0.0 on Ubuntu

March 27, 2013
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As you may (or may not) be aware of, R 3.0.0 is scheduled to be released on April 3rd. Since this is a major release and there may be some growing pains (but I hope not) in the move 3.0.0, here is some information about how I will handle R 3.0.0 on CR...

## Rationality, and MS Excel (and other calculators)

March 27, 2013
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$y^x$

This morning, Mathieu had a nice experience in his course on computational method in actuarial science. But let us start with some mathematical formal definitions. First, recall that is – somehow – a standard expression. No one should be surprised to see such an expression. Generally (as explained in http://en.wikipedia.org/… ), this function is defined only when . The...

## What does a data scientist do?

March 27, 2013
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The presentation below by Carlos Somohano (founder of Data Science London) provides the best description of a Data Scientist that I've seen in some time: Highlights include: On Slide 14, a history of the Data Science On Slide 22, the essential skills of data scientists (and a platypus) On Slide 26, 10 things data scientists do On Slide 27,...