Posts tagged racket

A HeatMap chart allows displaying a collection of GPS activities on a map and it is a nice way to visualize GPS data. On-line tools provide this functionality, but I wanted to implement my own, displaying heat maps using data from my own computer, without having to upload it to another website.

The Racket source code is distributed under LGPL and this means that any proprietary Racket application distributed must also provide a way for the user to re-link an updated Racket runtime and produce a new executable for that application. In this blog post we’ll explore how to achieve this.

I updated the map-widget package to allow map objects to snip%’s so it can be inserted into a pasteboard% and a side benefit of this work is that maps can now be embedded in the DrRacket REPL — while this was not why I did these modifications, it does make for a cool demo.

… in which we explore how to write internal Racket data structures to disk and read them back, and use these features to improve load times for the GeoJSON data, so the program does not have to spend 20 seconds in the initialization step.

… in which we use GeoJSON data for timezone boundaries to determine the time zone for a given location, and learn a few things about the performance of Racket programs.

The timezone-boundary-builder project publishes GeoJSON files with timezone boundaries based on OpenStreetMap data, and I though it would be an interesting project to load this data in Racket, build some map visualizations with it and explore some of the Racket drawing facilities.

With the future of Travis uncertain, I started looking for a Continuous Integration alternative and since Microsoft advertised Azure DevOps everywhere I went on the web, I decided to give it a try. I now moved all my Racket packages to Azure Pipelines, plus have a Racket application built with it, so I decided to write up some notes about my experience.

In the previous blog post, we built a password generator and packaged it as a command line utility, in this blog post we’ll look at how to build a GUI application with the same functionality and look at some of the techniques of building GUI applications in Racket.

There are many places in todays world where you need to provide a password and, since it is not recommended to reuse them, you will need to come up with many such passwords, all of them preferably secure. This blog post shows how to build a simple password generator. You may already use a password manager and may not have a need for a new one, still, this blog post might show you a few useful techniques for building Racket applications.

The Racket language provides a variety of ready-to-use data structures and containers, however each such container has advantages and disadvantages when it comes to performance. The “everything is a list” approach makes things simple when you are learning Racket, but if you start using it for more complex programs, you need to be aware that lists are not always the best data structure to use. This guide looks at a few alternatives.

When experimenting with a new data visualization or data analysis method, it is simpler to write a prototype as a separate application, to evaluate if it is worthwhile investing the effort of adding a full feature to ActivityLog2, this post illustrates the process used to write a “training load” dashboard application in Racket.

The Racket GUI library provides a text-field% control which allows input of arbitrary text, but only basic functionality by default. However, the class is designed to be extensible and in this article we’ll look at how to extend this control to provide a more modern input control with a cue text and input data validation.