### Euclid’s Doodle – and writing a visualization with Matplotlib

On page 110 of Professor Stewart’s Casebook of Mathematical Mysteries, he shows a neat visual way of calculating the GCD (Greatest common denominator, aka HCF, Highest common factor. Given a box with sides of two different lengths, draw squares from the lesser side until you can draw no more. Then continue from the corner the other direction. The smallest square has edge length of the GCD!

Continue reading “Euclid’s Doodle – and writing a visualization with Matplotlib”

### Adding BLM Land Use Maps to Osmand on Android

In the US, various hunters and fishers use the Bureau of Land Management’s maps. There are of course several apps that can let you add BLM maps…

• Avenza has some maps provided by BLM specifically for avenza app.
• Gaia maps pro has had the public lands feature for years.
• Osmand has not the greatest support for viewing what land area you are in and looking at, but many local points of interest are in this app that are not in others as it uses the Openstreetmap which can be added and edited by locals with places they actually care about. Also unlike most other offline mapping apps it is open-source, available on F-Droid store, and very extensive, and respects user freedoms and an active developer community.

For some time I have wondered why the public domain BLM land use maps aren’t an option in Osmand, I tried mobac but found no way to get the maps I wanted, but after a bit of research I found the answer! Here are the steps to add land use maps to Osmand. Continue reading “Adding BLM Land Use Maps to Osmand on Android”

### Neural Networks Part 2: Learning Pi

Thousands of years ago, probably around the invention of the wheel, and before the time of Solomon, humans must have been measuring various objects… calculating some distances, and wondering,  is there a better way to measure how far around the outside of a wheel is compared to its diameter? Continue reading “Neural Networks Part 2: Learning Pi”

### The only metric guide you may need

Kilometers, Centimeters… microfarads, farads… They units are all a multiple of 10, but that doesn’t make them that much easier as you are first learning them. What is 1.09km in cm? or 1205cm in km? With a quick jotted down note card you can very quickly see what any commonly used metric unit converts to!

### Setting up AREDN node with Ubiquiti Nanostation with Ubuntu

If your area has other ham-radio operators that are using an AREDN network, an Ubiquity router is a great way to connect to the local LAN network. Note that you will need: