Articles by Michael Bedward

packcircles version 0.2.0 released

April 7, 2017 | 0 Comments

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 has a new circleProgressiveLayout function. It uses an efficient deterministic algorithm to arrange circles by consecutively placing each one externally tangent ...
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Graph-based circle packing

July 27, 2015 | 0 Comments

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 circles until (hopefully) a non-overlapping arrangement emerged. In this post we'll look an alternative approach. An algorithm to find an arrangement ... [Read more...]

Graph-based circle packing

July 27, 2015 | 0 Comments

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 circles until (hopefully) a non-overlapping arrangement emerged. In this post we'll look an alternative approach. An algorithm to find an arrangement ... [Read more...]

Static and moving circles

May 29, 2015 | 0 Comments

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 argument to the circleLayout function. Weights can be in the range 0-1 inclusive, where a ... [Read more...]

Circle packing in R (again)

April 29, 2015 | 0 Comments

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 circleLayout which takes a set of overlapping circles and tries to find a non-overlapping ... [Read more...]

Fitting an ellipse to point data

September 30, 2012 | 0 Comments

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 bit hacky, returning odd results for some data. A couple of days ... [Read more...]

Monte Carlo testing of classification groups

September 1, 2010 | 0 Comments

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 the same level accounts for the variability in the da...
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Homogeneity analysis of hierarchical classifications

August 10, 2010 | 0 Comments

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++. A recent query on the r-help list, about how to det...
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Circle packing with R

July 26, 2010 | 0 Comments

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 more than a specified amount. A colleague had approa...
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