One criticism that is often leveled against using resampling methods (such as cross-validation) to measure model performance is that there is no correlation between the CV results and the true error rate. Let's look at this with some simulated data. W...

This is a very short post on mapping with ggplot2.

This is the story of a subtle error that, to my opinion, is a nice example of the special challenges of statistical programming. One of my main research interests is time series with long memory. These are often modeled by fractionally integrated models, where Here is the time series, is ...

Another interesting thing that an R course participant identified: Sometimes one wants to make a function that returns multiple layers to be added to a ggplot2 plot. One could think that just adding them and returning would work, but it doesn’t. I think it has to do with how + ...

The classification decisions made by machine learning models are usually difficult - if not impossible - to understand by our human brains. The complexity of some of the most accurate classifiers, like neural networks, is what makes them perform so wel...

This guide is part of a series on setting up your own private server running shiny apps. There are many guides with great advice on how to set up an R shiny server and related software. I try to make a comprehensive guide based in part on these resourc...

In real estate, spatial data is the name of the game. Countless other domains utilize the power of this data, which is becoming more prevalent by the day. In this post I will go over a few simple, but powerful tools to get you started using using geographic information in ...

This week, I am exploring Holger K. von Jouanne-Diedrich’s OneR package for machine learning. I am running an example analysis on world happiness data and compare the results with other machine learning models (decision trees, random forest, gradient...

Analytical challenges in multivariate data analysis and predictive modeling include identifying redundant and irrelevant variables. A recommended analytics approach is to first address the redundancy; which can be achieved by identifying groups of variables that are as correlated as possible among themselves and as uncorrelated as possible with other variable ...

I caught this “gem” in the Wall Street Journal tonight: It’s pretty hard to compare store-to-store, even though it is fairly clear which ones are going-going-gone. If we want to see the relative percentage of each store closing and also want to see how they stack up against each ...

R is a very fluid language amenable to meta-programming, or alterations of the language itself. This has allowed the late user-driven introduction of a number of powerful features such as magrittr pipes, the foreach system, futures, data.table, and dplyr. Please read on for some small meta-programming effects we have ...

This week’s R bulletin will cover topics like how to avoid for-loops, add or shorten an existing vector, and play a beep sound in R. We will also cover functions like env.new function, readSeries, and the with and within functions. Hope you like this R weekly bulletin. Enjoy ...

The data analyzed in this post come from RePEc which is a collaborative project well-known by economists. It gathers links to working papers, journal articles or software components and also provides a ranking of more than 30,000 registered economists. This ranking is calculated by taking a harmonic mean of the ranks ...