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Measures of confusion with JSR-275
I love the idea behind JSR-275, a units of measurement API for Java (see here for a background article by Jean-Marie Dautelle, the lead author) but I wish there were more examples out there about how...
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Unleash your inner literary geek
Those good fellows at Pragmatic Programmers have come up with the geeky equivalent of NaNoWriMo - the annual event that encourages people to try their hand at writing - which they have christened...
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PragProWriMo begins
November is here and this not-so-young-anymore geek's heart has turned to writing. I'm taking up the challenge of PragProWriMo by committing (forcing, tricking...) myself to write every day. The target...
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PragProWriBlockMo
PragProWriMo has been even more challenging than I'd feared thanks to my sub-gnat concentration span and memory like a... you know, round thing with holes. While others have been trotting out chapter...
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K ?
Whisper the terrible words type erasure to any moderately experienced Java programmer and you're likely to see: fear loathing soul-crushing sense of defeat all of the aboveNow if you are a moderately...
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Cubic spline interpolation
I spent a while today casting around for a simple, fast and just-good-enough cubic interpolation algorithm to use in the GeoTools library where it is to serve as a 'filter function' that can be used...
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A clip round the ear
Inspired by a recent discussion on the JTS user list about decomposing simple polygons into triangles, here is a program that demonstrates the brute force, ear-clipping algorithm. To run this you will...
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Another clip round the ear
In the last episode I presented some code to triangulate a polygon using the ear-clipping algorithm. In this instalment the code has been extended to deal with polygons that have holes. Here are two...
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Circle packing with R
To visualize the results of a simulation model of woodland trees within R, I needed an algorithm that could arrange a large number of circles within a rectangle such that no two circles overlapped by...
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Meeting in the middle; or fudging model II regression with nls
My colleague Karen needed an equation to predict trunk diameter given tree height, which she hoped to base on measurements of trees in semi-arid Australian woodlands. This is the dark art of allometry...
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Homogeneity analysis of hierarchical classifications
I've spent more years than I care to remember analysing vegetation survey data (typically species abundances in plots) using a variety of software including my own algorithms coded in FORTRAN and C++....
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Fun with the proto package: building an MCMC sampler for Bayesian regression
The proto package is my latest favourite R goodie. It brings prototype-based programming to the R language - a style of programming that lets you do many of the things you can do with classes, but with...
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Monte Carlo testing of classification groups
This is another article on the theme of defining groups in a hierarchical classification. A previous article described homogeneity analysis to visualize how any well any number of groups, defined at...
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Smooth as...
For a current project I needed a polygon smoothing algorithm in Java that: generated a curve passing through all polygon vertices had some way of controlling tightness of fit to the polygon fell within...
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Build an application plus a separate library uber-jar using Maven
I've been working on a small Java application with a colleague to simulate animal movements and look at the efficiency of different survey methods. It uses the GeoTools library to support map...
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IDE errors with Maven projects after upgrading to NetBeans 7.2
A recent upgrade of NetBeans from version 7.1 to 7.2 seemed to cause problems with Maven multi-module projects. Normally, a newly created class in one Maven project module will be instantly visible to...
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Fitting an ellipse to point data
Some time ago I wrote an R function to fit an ellipse to point data, using an algorithm developed by Radim Halíř and Jan Flusser1 in Matlab, and posted it to the r-help list. The implementation was a...
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Circle packing in R (again)
Back in 2010 I posted some R code for circle packing. Now, just five years later, I've ported the code to Rcpp and created a little package which you can find at GitHub.The main function is...
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Static and moving circles
After the previous post on the packcircles package for R someone suggested it would be useful to be able to fix the position of selected circles. As a first attempt, I've added an optional weights...
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Graph-based circle packing
The previous two posts showed examples of a simple circle packing algorithm using the packcircles package (available from CRAN and GitHub). The algorithm involved iterative pair-repulsion to jiggle the...
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packcircles version 0.2.0 released
Version 0.2.0 of the packcircles package has just been published on CRAN. This package provides functions to find non-overlapping arrangements of circles in bounded and unbounded areas. The package how...
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