SMACOF stands for “Scaling by MAjorizing a COmplicated Function,” and it is a multidimensional scaling algorithm for metric unfolding of, among other things, rectangular ratings matrices. One neat Political Science application of MDS is i...

Consider the following "magic" 3-gon ring, filled with the numbers 1 to 6, and each line adding to nine. Working clockwise, and starting from the group of three with the numerically lowest external node (4,3,2 in this example), each solution can be described uniquely. For example, the above solution can be described by the...

Redos of the plots from this post: Bit more communicative, though the overplotting is a bit annoying. Code: ## gis libraries library(spBayes) library(MBA) library(geoR) library(fields) library(sp) library(maptools) library(rgdal) library(classInt) library(lattice) library(xtable) library(spatstat) library(splancs) ## Other packages library(ggplot2) library(foreign) library(stringr)...

This is my new website! It’s built using jekyll-bootstrap and hosted on Github.

Today I want to follow up with the XLLoop framework post. Please read the XLLoop framework post first to setup the XLLoop before trying the examples below. My first example is based on the TFX Package – to retrieve real-time FX quotes. To try this example, please first install the TFX Package. Please note that

As posted here a long, long while ago, following a suggestion from the editor (and North America Cycling Champion!) Pierre Lécuyer (Université de Montréal), Arnaud Doucet (University of Oxford) and myself acted as guest editors for a special issue of ACM TOMACS on Monte Carlo Methods in Statistics. (Coincidentally, I am attending a board meeting

A few quick plots of West Baltimore neighborhoods, first Sandtown-Winchester: and Harlem Park: These aren’t very polished, I’ll put up better versions. Here’s the code for those that want it: ## gis libraries library(spBayes) library(MBA) library(geoR) library(fields) library(sp) library(maptools) library(rgdal)...