R

Blogs on the R software.

intuition beyond a Beta property

March 29, 2015
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intuition beyond a Beta property

A self-study question on X validated exposed an interesting property of the Beta distribution: If x is B(n,m) and y is B(n+½,m) then √xy is B(2n,2m) While this can presumably be established by a mere change of variables, I could not carry the derivation till the end and used instead the moment generating function E[(XY)s/2] […]

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Space Launch Sites over Time

March 29, 2015
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Space Launch Sites over Time

Continuing from last weeks post, I am now looking at space launch sites.DataData are from the main table. In addition, this sites table was manually browsed for interpretation of abbreviations.List of most important sitesJust by running counts the most...

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R style default plot for Pandas DataFrame

March 28, 2015
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R style default plot for Pandas DataFrame

The default plot method for dataframes in R is to show each numeric variable in a pair-wise scatter plot. I find this to be a really useful first look at a dataset, both to see correlations and joint distributions between variables, but also to quickly diagnose potential strangeness like bands of repeating values or outliers. […]

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Google Scholar Finds Far More SPSS Articles; Analytics Forecast Updated

March 26, 2015
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Google Scholar Finds Far More SPSS Articles; Analytics Forecast Updated

Only last August I wrote that among scholars, the use of R had probably exceeded that of SPSS to become their most widely used software for analytics. That forecast was based on Google Scholar searches focused on one year at a … Continue reading →

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Le Monde puzzle [#904.5]

March 25, 2015
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Le Monde puzzle [#904.5]

About this #904 arithmetics Le Monde mathematical puzzle: Find all plural integers, namely positive integers such that (a) none of their digits is zero and (b) removing their leftmost digit produces a dividing plural integer (with the convention that one digit integers are all plural). a slight modification in the R code allows for a […]

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ChainLadder 0.2.0 adds Solvency II CDR functions

March 24, 2015
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ChainLadder 0.2.0 adds Solvency II CDR functions

ChainLadder is an R package that provides statistical methods and models for claims reserving in general insurance.With version 0.2.0 we added new functions to estimate the claims development result (CDR) as required under Solvency II. Special thanks t...

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Factor Evaluation in Quantitative Portfolio Management

March 23, 2015
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Factor Evaluation in Quantitative Portfolio Management

When it comes to managing a portfolio of stocks versus a benchmark the problem is very different from defining an absolute return strategy. In the former one has to hold more stocks than in the later where no stocks at all can be held  if there is not good enough opportunity.  The reason for that is the tracking error. This […]

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Launch into space

March 22, 2015
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Launch into space

I saw a link to a list with all rocket launches into space the other day. This post contains some plots concerning day of launch made from that.DataData is a fixed format file with eleven columns. Reading fixed format is not very difficult, however, it...

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I’m all about that bootstrap (’bout that bootstrap)

March 21, 2015
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I’m all about that bootstrap (’bout that bootstrap)

As some of my regular readers may know, I'm in the middle of writing a book on introductory data analysis with R. I'm at the point in the writing of the book now where I have to make some hard… Continue reading →

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It’s Analytics Survey Time!

March 20, 2015
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It’s Analytics Survey Time!

Every other year Rexer Analytics surveys Data Analysts, Predictive Modelers, Data Scientists, Data Miners, and all other types of analytic professionals, students, and academics regarding the software they use.  I then update the main results in The Popularity of Data Analysis … Continue reading →

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