Web Beacon API

There’s a sweet little function in web browsers called the Web Beacon API.  It’s a simplified version of the XHR or Fetch API that does a fire-and-forget POST operation to a server. It’s nice for a few reasons.  First, browser Javascript (front-end Javascript) can use it without any need to process results coming back. Just … Read more

Database programming

This entry is part 3 of 4 in the series Exploring data with SQL

In the last section, we populated our us_counties table and used it for some queries. Now it’s time to create some views of the data. With views we’ll be able to do more interesting things without retyping huge queries. We can use views as a foundation for more analysis. The first view we need is … Read more

Find peak cases

This entry is part 4 of 4 in the series Exploring data with SQL

Back in the Database Programming section of this series, we created the view named us_counties_new, showing the daily new case load. Recall that we first computed the seven-day running average of the total case loads in the us_counties_avg7 view, then used those numbers for the daily case loads. Having the daily case loads available lets … Read more

Getting started with the data

This entry is part 2 of 4 in the series Exploring data with SQL

The Times’s data is here. https://raw.githubusercontent.com/nytimes/covid-19-data/master/us-counties.csv If you’re using a browser, open the context menu (right-click) on that link and use the Save Link As … operation to put it into a file on your system. We’ll use it later to load the database. Use your database interface program to log in to your database … Read more

Choropleths: color-coded maps showing data by state or other geography

A Choropleth is a colored map, typically showing information gathered by some kind of census. A well-known example is the New York Times’s COVID-19 map. Let’s say you have some data that’s coded by geographic area. For example, you might have a table showing the number of COVID cases per 100,000 people county by county in … Read more

getDisplayMedia vs. getUserMedia

I’ve been messing around with the browser API navigator.mediaDevices.getDisplayMedia(). The question I hoped to answer: can I capture the content in some computer display surface and push it through the same sorts of process that I use with .getUserMedia()? I tested on Google Chrome 84. Answer: yes. It has some quirks. It doesn’t need, and … Read more