SEM Time Series Modeling

Structural Equation Models (SEM) which are common in many economic modeling efforts, require fitting and simulating whole system of equations where each equation may depend on the results of other equations. In this post, we will show how to do structural equation modeling in R by working through the Klein Model of the United States economy, one of the oldest and most elementary models of its kind.

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A Custom Forest Plot from Wonderful Wednesdays

This post takes a closer look at the forest plot that was mentioned in a previous post introducing PSI’s Wonderful Wednesdays events. It describes a custom version of a forest plot with additional bands to visualize heterogeneity between studies in a meta-analysis that was part of a project submitted to the Wonderful Wednesdays challenge hosted by PSI and reviewed by statisticians in the organization.

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Wonderful Wednesdays

For almost a year now, the PSI Visualization Special Interest Group (VIS SIG) has been conducting a monthly graduate-level seminar on creating effective statistical visualizations that is open to everyone. Wonderful Wednesdays is a unique collegial event. Every month the SIG publishes a link to a new data set and issues a challenge to produce visualizations that effectively illustrate some specific aspects of the data. Anyone can submit an entry coded in the language of their choice.

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COVID-19 Data: The Long Run

The world seems to have moved to a new phase of paying attention to COVID-19. We have gone from pondering daily plots of case counts, to puzzling through models and forecasts, and are now moving on to the vaccines and the science behind them. For data scientists, however, the focus needs to remain on the data and the myriad issues and challenges that efforts to collect and curate COVID data have uncovered.

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November: "Top 40" New CRAN Packages

Two hundred ninety-two new packages made it to CRAN in November. Picking forty was unusually difficult. Nevertheless, here are my “Top 40” selections in twelve categories: Archaeology, Computational Methods, Data, Epidemiology, Games, Machine Learning, Mathematics, Medicine, Statistics, Time Series, Utilities, and Visualization. R developers continue to extend the reach of R. November featured a new package on Archaeology, one of only seventeen I could find on CRAN pkgsearch::pkg_search(query="Archaeology ",size=200), as well as a package that wraps Python’s chess package.

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Plotting Surfaces with R

This post takes a look at some basic R tools for producing eye catching three dimensional plots of surfaces and probability distributions. It showcases some interactive JavaScript enabled interactive plots along with classsic visualizations built on base R graphics.

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Learn and Teach R

If you haven’t explored the RStudio website in a while, your next visit may include a pleasant surprise. I recently went to the Tidymodels page, just to see what was new and was immediately drawn into the new landscape imagined by the RStudio education team. Clicking on Get Started I came to a fork and a choice of going farther with Tidymodels or backing up a bit. I went down the beginners path Finding Your Way to R and found myself in a well-lit wood, and I was not lost.

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COVID-19 Mobility Data

We are in the middle of a mind-boggling natural experiment here in the United States. In spite of the advice from the CDC and dire warnings from our nation’s health care experts, millions of Americans will travel over the long holiday weekend. Although the number of people flying is significantly down from last year, there are still large numbers of Americans on the move. The TSA reported that more than two million people went through airport checkpoints last weekend, and the AAA is forecasting as many as fifty-million people may travel.

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October 2020: "Top 40" New CRAN Packages

One hundred fifty-six new packages made it to CRAN in October. Here are my “Top 40” selections in eight categories: Computational Methods, Data, Epidemiology, Mathematics, Machine Learning, Statistics, Utilities, and Visualization. Featured packages include tdaunif for sampling from manifolds, SoundShape for exploring the shape of sound, and anscombiser that hints at the potential fragility of machine learning models.

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ROC Day at BARUG

This week, the Bay Area useR Group (BARUG) held a mini-conference focused on ROC Curves. Talks discussed the history of the ROC, extending ROC analysis to multiclass problems, various ways to think about and interpret ROC curves, and how to translate concrete business goals into the ROC framework, and pick the optimal threshold for a given problem.

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