2610 search results for "GIS"

Measuring user retention using cohort analysis with R

April 27, 2012
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Measuring user retention using cohort analysis with R

Cohort analysis is super important if you want to know if your service is in fact a leaky bucket despite nice growth of absolute numbers. There’s a good write up on that subject “Cohorts, Retention, Churn, ARPU” by Matt Johnson. So how to do it using R and how to visualize it. Inspired by examples

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Randomization thoughts

April 27, 2012
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Randomization thoughts

Le Grand Casino of Monte CarloOn Monday I’m going to be leading a little stats workshop on randomization tests and null models. In preparation for this I wrote up code for null model examples I wanted to write a post that introduced the basics of these models (Null models, bootstrapping,...

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Structural Breaks (Bull or Bear?)

April 26, 2012
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Structural Breaks (Bull or Bear?)

When I spotted the bfast R package, I could not resist attempting to apply it to identify bull and bear markets.  For all the details that I do not understand, please see the references: Jan Verbesselt, Rob Hyndman, Glenn Newnham, Darius Culvenor...

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Graphic Parameters (symbols, line types, and colors) for ggplot2

April 26, 2012
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Graphic Parameters (symbols, line types, and colors) for ggplot2

Following up on John Mount’s post on remembering symbol parameters in ggplot2, I decided to give it a try and included symbols, line types, and colors (based upon Earl Glynn’s wonderful color chart).  Code follows below.    

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More PubMed data mining: looking at top 20 CBT journals

April 26, 2012
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More PubMed data mining: looking at top 20 CBT journals

In this short article I present some data of the top 20 Cognitive Behavior Therapy (CBT) journals with the most PubMed publications, and compare that to data from 2010 and 2011.

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Installing R packages without admin rights on MS Windows

April 26, 2012
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Installing R packages without admin rights on MS Windows

Is there a life outside the office?Photo: Markus GesmannIt is not unusual that you will not have admin rights in an IT controlled office environment. But then again the limitations set by the IT department can spark of some creativity. And I have to ad...

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Insights into Quantile Regression from Arthur Charpentier

April 24, 2012
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Insights into Quantile Regression from Arthur Charpentier

At this Monday’s Montreal R User Group meeting, Arthur Charpentier gave an interesting talk on the subject of quantile regression. One of the main messages I took away from the workshop was that quantile regression can be used to determine if extreme events are becoming more extreme. The example given was hurricane intensity since 1978.

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Rmetrics financial engineering workshop

April 24, 2012
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For those looking for an in-depth workshop on financial engineering with R, look no further than the R/Rmetrics Workshop and Summer School held annually in beautiful Meielisalp, Switzerland. This is an intimate workshop limited to around 50 participants, and features tutorials from leading practitioners in finance with R. This year's workshop takes plase June 24-28. You can find the...

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Milano R net meeting

April 24, 2012
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Milano R net meeting

I received the announce of the first Milano R net meeting, and I am glad to post it below. If you are based in Milano area you might think about going. If you are not based in Milano area, you might think about going as well! Milano R net Milano R net is a users

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Drawdown Look at Frontier of Assets and Systems

April 23, 2012
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Drawdown Look at Frontier of Assets and Systems

In Efficient Frontier of Funds and Allocation Systems, I had hoped to start exploring how a frontier can potentially be created with only one asset, or how an even more efficient frontier could be created with assets and also systems on those assets.&n...

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