Shaded Area Plot

:: racket, data visualization

… in which we explore using interval renderers and color maps to create a plot where the area under the line is shaded based on data from a second data series.


Box and Whiskers Plot

:: racket, data visualization

The Box and Whiskers plot is a method for depicting groups of numerical data through their quartiles and it is a popular way to depict statistical information about data sets, yet the Racket plot package does not support such a plot type. In this blog post we’ll explore how to add this plot type to the plot package without having to modify the package itself, and we’ll look at some useful techniques of extending the plot package.


Climb Analysis Tool

:: racket, activitylog2, data visualization

As part of preparing for a bicycle race in my local city I wanted to look at the climbs of the bike route and evaluate their difficulty. Since all the (free) online tools only provided basic analysis tools, I decided to write my own.


Plot Animations

:: racket, data visualization

There is no specific animation function in the Racket plot package, but animations can be build by repeatedly plotting individual frames onto a canvas or image using plot/dc. The technique requires drawing the entire plot every frame, which will be inefficient for complex plots. In this blog post we explore how to construct plot animations using the set-overlay-renderers method of a plot snip, which is a more efficient method when plots are embedded in GUI applications.


Space Invaders

:: games in racket, racket

… in which we attempt to recreate a classic game using the Racket graphical facilities and exploring classes and objects.


Rendering the World Map Using the Racket Plot Package

:: racket, data visualization

As part of writing the geoid package, I needed to visualize some geographic projections and I discovered that the 3D plotting facilities in the racket plot package can be easily used for this task. The geoid package and the projection it uses is somewhat complex, so, to keep things simple, this blog post covers the display of the country outlines on a globe loading the data from the GeoJSON file and using only basic plotting facilities.


Barometric Altitude Measurement

:: training data analysis

While analyzing the data from my latest indoor trainer ride, I noticed that my FR–920 records altitude while running in “Indoor Trainer” mode. This means that I have a lot of altitude measurements at what is effectively the same elevation, so I had a look at how good altitude measurement really is.


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