Anytime I get a new hammer, I waste no time in trying to find something to bash with it. Prior to last year, I wouldn’t have known what a cluster was, other than the first half of a slang term used to describe a poor decision-making process. Now I’... [Read more...]

[This article was first published on Rmetrics blogs, and kindly contributed to R-bloggers]. (You can report issue about the content on this page here) Want to share your [Read more...]

Lloyd's of London is looking for a Data Scientist as part of the Analysis team. See Lloyd's career web site for more details. [Read more...]

Sometimes I want to use R to fill in values that are missing in one data frame with values from another. For example, I have data from the World Bank on government deficits. However, there are some country-years with missing data. I gathered data from ... [Read more...]

This morning, I was working on some paper on inequality measures, and for computational reasons, I had to sort elements in a matrix. To make it simple, I had a rectangular matrix, like the one below, __ set.seed(1) __ u=sample(1:(nc*nl)) __ (M1=matrix(u,nl,nc)) [,1] [,2] [,3] [,4] [,5] [,6] [1,] 7 5 11 23 6 17 [2,] 9 18 1 21 24 15 [3,] 13 19 3 8 22 2 [4,] 20 12 14 16 4 10 I had to ... [Read more...]

Today, I want to share the January Seasonality application (code at GitHub). This example is based on the An Example of Seasonality Analysis post. This is the third application in the series of examples (I plan to share 5 examples) that will demonstrate the amazing Shiny framework and Systematic Investor Toolbox ... [Read more...]

If you haven't sent your loved one a Valentine's Day greeting yet, it's not too late! Thanks to Guillermo Santos who pointed out an R script from Berkeley's Concepts in Computing with Data course, I created the following Valentine's Day card for my husband: If you want to make one ... [Read more...]

There are many different maps you can use for a background map for your gps or other latitude/longitude data (i.e. any time you're using geom_path, geom_segment, or geom_point.)get_mapHelpfully, there's just one function that will allow you to query Google Maps, OpenStreetMap, Stamen maps, ... [Read more...]

This post will describe linear regression as from the book Veterinary Epidemiologic Research, describing the examples provided with R. Regression analysis is used for modeling the relationship between a single variable Y (the outcome, or dependent variable) measured on a continuous or near-continuous scale and one or more predictor (independent ... [Read more...]

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Working on a quick-and-dirty simulation of people wandering around until they find neighbors, then settling down. After playing with the coloring a bit I arrived at the above image, which I quite like. Code below: # Code by Matt Asher for statisticsblog.com # Feel free to modify and redistribute, but please ... [Read more...]

Several packages on CRAN provide (or relate to) interfaces between databases and R.  Here is a summary, mostly in the words of the package descriptions.  Remember that package names are case-sensitive. The packages that talk about being DBI-compliant are referring to the DBI package (see below in “Other SQL”). MySQL ... [Read more...]

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Version 1.0 of multilevelPSA has been released to CRAN. The multilevelPSA package provides functions to estimate and visualize propensity score models with multilevel, or clustered, data. The graphics are an extension of PSAgraphics package by Helmreich and Pruzek. The example below will investigate the differences between private and public school internationally ... [Read more...]

Everyone in academia knows how painful the peer-review publication process can be. It’s a lot like Democracy, in that it’s the worst system ever invented, except for all the others. The peer-review process does a fair job at promoting good … Continue reading → [Read more...]

Hello. Welcome to my debut post ! Check the About link to see what this Blog intends to accomplish. In this article I discuss a general approach for dealing with the problem of splitting a data frame based on a grouping variable and then doing some more operations per group. A ... [Read more...]

Today, I want to share the Multiple Stocks Plot application (code at GitHub). This is the second application in the series of examples (I plan to share 5 examples) that will demonstrate the amazing Shiny framework and Systematic Investor Toolbox to analyze stocks, make back-tests, and create summary reports. The motivation ... [Read more...]

In case you missed them, here are some articles from January of particular interest to R users. Anthony Damico created an amusing and useful flowchart for finding resources for learning R, especially for survey analysis. All R users: please be counted for the 2013 Rexer Data Miner Survey (R was the #1 ... [Read more...]

It is common to fit a model using training data, and then to evaluate its performance on a test data set. When the data are time series, it is useful to compute one-step forecasts on the test data. For some reason, this is much more commonly done by people trained ... [Read more...]

Mason Earles gave a great presentation this week at Davis R Users’ Group about linking R with the Forest Vegetation Simulator (FVS). FVS is a model developed by the US Forest Service to simulate forest growth over time. It’s written in FORTRAN and has been around since the 1970s. ... [Read more...]