Hello morphometricians,Below you can find a new fixed angle function addressing the problem discovered by Fabio Machado in the morphmet mail archive. We will include this function in our next schedule update to geomorph. Cheers, Erik CODE: fixed.angle [Read more...]

I am preparing for a workshop on mixed models and looked at the paper “Accounting for multilevel data structures in fisheries data using mixed models” by Wagner et al. (2006) (PDF available here).  Wagner et al. (2006) used two examples, with the … Continue reading → [Read more...]

How to get from a txt-file with short names and labels to a QGIS-Style (qml-file)? I used the below R-script to create a style for this legend table where I copy-pasted the parts I needed to a txt-file, like for the WRB-FULL (WRB-FULL: Full soil code o... [Read more...]

What’s that thing about arithmetic and geometric returns and the variance? Previously An introduction to the difference between simple and log returns is: A tale of two returns Issue Suppose you are predicting the mean annual return of an asset for some number of years.  To simplify the discussion, ... [Read more...]

the social security administration (ssa) must be overflowing with quiet heroes, because their public-use microdata files are as inconspicuous as they are thorough.  sure, ssa publishes enough great statistical research of their own that outside re... [Read more...]

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Some months ago, I had to explore a vast amount of categorical variables before making some multivariate analyses. One good way to know your raw data, to make new hypotheses…etc, is to calculate some pairwise “crude” chi-square tests of independence … Sigue leyendo → [Read more...]

Introduction Today, I will talk about the math behind calculating partial correlation and illustrate the computation in R with an example involving the oxidation of ammonia to make nitric acid using a built-in data set in R called stackloss.  In a separate post, I will also share an R function ... [Read more...]

I took the SNA course by Lada Adamic in coursera. It's a super interesting course. In fact, I was using the networks only how a visualization tool, and that is what it make me little bit embarrassing because there are more, a lot of more. You can detec... [Read more...]

There is about two weeks remaining until R/Finance 2013 - being held on May 17th and 18th at UIC in Chicago.  Make sure you register beforehand to ensure you have a spot, and – yes - you do want to come to the conference dinner on Friday.   I am particularly excited ... [Read more...]

After last post's setting up for a simulation, it is now time to look how the models compare. To my disappointment with my simple simulations of assessors behavior the gain is minimal. Unfortunately, the simulation took much more time than I ... [Read more...]

Adam Duncan from January, 2013Also avilable on R-bloggers.com Strategy Implications In this part of the volatility regimes analysis, we’ll use the regime identification framework established in part 1 to draw conclusions about which strategies work best is each regime. That should prove useful to us and goes a long ... [Read more...]

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Model selection is a process of seeking the model in a set of candidate models that gives the best balance between model fit and complexity (Burnham & Anderson 2002). I have always used AIC for that. But you can also…Read more → [Read more...]

I’ve been asked many time if I have a piece of R code implementing the monotonic binning algorithm, similar to the one that I developed with SAS (http://statcompute.wordpress.com/2012/06/10/a-sas-macro-implementing-monotonic-woe-transformation-in-scorecard-development) and with Python (http://statcompute.wordpress.com/2012/12/08/monotonic-binning-with-python). Today, I finally had time to draft a quick ... [Read more...]

Today (May 4, 2013) I will begin the process of backporting R 3.0.0 to Quantal, Precise, and Lucid. This will include all the recommended packages and the packages for R found in the universe repository for Ubuntu. Things to keep in mind: If you do... [Read more...]

A nice post was recently published on the rsnippets blog, about the tikzDevice R package. This package is – indeed – awesome. Even if it has been removed from the CRAN website. Of course, it can be download from the archive folder, on http://cran.r-project.org/…, but also (for a more ... [Read more...]

Just a short post, to share some codes used to generate animated graphs, with R. Assume that we would like to illustrate the law of large number, and the convergence of the average value from binomial sample. We can generate samples  using __ n=200 __ k=1000 __ set.seed(1) __ X=matrix(sample(0:1,size=... [Read more...]

Parallel coordinates become much more useful when they are interactive, so I recreated one of my favorite blog posts "Trend is Not Your Friend" Applied to 48 Industries and convert the chart to a living breathing d3 parallel coordinates chart courtesy ... [Read more...]