Last year, in a post, I discussed how to merge levels of factor variables, using combinatorial techniques (it was for my STT5100 cours, and trees are not in the syllabus), with an extension on trees at the end of the post. consider the following (simulated dataset) n=200 set.seed(1) x1=...

Last week, in our STT5100 (applied linear models) class, I’ve introduce the hat matrix, and the notion of leverage. In a classical regression model, (in a matrix form), the ordinary least square estimator of parameter is The prediction can then be writtenwhere is called the hat matrix. The matrix ...

As far as rivalries go, R vs Python can almost reach the levels of the glory days of Barca vs Madrid, Stones vs Beatles, or Sega vs Nintendo. Almost. Just dare to venture onto Twitter asking which language is best for data science to witness two tightly entrenched camps. Or ...

As far as rivalries go, R vs Python can almost reach the levels of the glory days of Barca vs Madrid, Stones vs Beatles, or Sega vs Nintendo. Almost. Just dare to venture onto Twitter asking which language is best for data science to witness two tightly entrenched camps. Or ...

“I am working on a simulation study that requires me to generate data for individuals within clusters, but each individual will have repeated measures (say baseline and two follow-ups). I’m new to simstudy and have been going through the examples in R this afternoon, but I wondered if this ...

Another low-key arithmetic problem as Le Monde current mathematical puzzle: Find the 16 integers x¹,x²,x³,x⁴,y¹,y²,y³,y⁴,z¹,z²,z³,z⁴,w¹,w²,w³,w⁴ such that the groups x¹,y¹,z¹,w¹, &tc., are made of distinct positive integers, the sum of the x’s ...

If you follow the #rstats news on Twitter, you have most likely seen the impressive 3D maps produced with Tyler Morgan-Wall’s rayshader package. I’ve been wanting to try it for a long time and I finally found the time to do it last week. As a limnologist living ...

Which season of the bachelor really was the most dramatic ever? Analyze the relative popularity of the bachelor franchise seasons as measured by their google search traffic using R, gtrendsR, ggplot2, ggimage and gganimate!

Cross-validation is a widely used technique to assess the generalization performance of a machine learning model. In this blog post I will introduce the basics of cross-validation, provide guidelines to tweak its parameters, and illustrate how to build it from scratch in an efficient way. Der Beitrag Evaluating Model Performance ...

Kannada MNIST dataset is another MNIST-type Digits dataset for Kannada (Indian) Language. All details of the dataset curation has been captured in the paper titled: “Kannada-MNIST: A new handwritten digits dataset for the Kannada language.” by Vinay Uday Prabhu. The github repo of the author can be found here. The ...

The wonderful package ggdag can easily make DAG like this:However, what we really want to include in publications is something like this:The second one can include subscript and superscript, among many others. After some tweaking, I found a solution, n...

The wonderful package ggdag can easily make DAG like this: However, what we really want to include in publications is something like this: The second one can include subscript and superscript, among many others. After some tweaking, I found a solution, not perfect but usable for now.-----------------------------------------------------------------library(dagitty)library(...