After a two-week hiatus, we’re back with another installment of FSR. This week we look at GAP (Groups, Algorithms, Programming), a “system for computational discrete algebra, with particular emphasis on Computational Group Theory”. GAP is another freebie, and it has a very large user community that has produced dozens of add-on packages to increase its functionality. Keep reading.

## Posts Tagged ‘free software’

### Friday Software Review: GAP

December 7, 2007### Friday Software Review: Maxima

November 16, 2007This week we’ll look at Maxima, a computer algebra software (CAS) program. From the website:

Maxima is a system for the manipulation of symbolic and numerical expressions, including differentiation, integration, Taylor series, Laplace transforms, ordinary differential equations, systems of linear equations, polynomials, and sets, lists, vectors, matrices, and tensors…Maxima can plot functions and data in two and three dimensions.

It has many of the same functions and capabilities as Maple and Mathematica and costs several hundred dollars less. Read on

### Friday Software Review: GeoGebra

November 9, 2007In the first of what I hope to be a (nearly) weekly column, I’ll review GeoGebra, a free geometry software package.

GeoGebra is similar to Geometer’s Sketchpad in that you can perform all of the standard ruler-and-compass constructions (e.g., bisecting a segment, bisecting an angle), but you can also enter algebraic equations. So if you want to work with a circle, you can enter the equation directly, or you can create a point and use it as the center to draw a circle with the “circle” tool (GeoGebra will then find the equation for you, if you want). Here’s the construction of a regular pentagon in progress (click for full-size):

The interface is fairly intuitive. I didn’t need to refer to the documentation at all to do my first construction (the pentagon). In my attempt to construct the heptadecagon, round-off error caused the last side to be off slightly, and I haven’t tried again lately (because really, who wants to follow the instructions to construct a 17-sided polygon *twice*?), so I don’t know if that has been fixed.

GeoGebra is Java-based, so it’s a little slow to load (as are all Java apps), but you can download the whole thing and install it locally. It’s a nice thing to have when you’re not at school and can’t get to Geometer’s Sketchpad, and it generates very nice pictures if you need to include some in a document (LaTeX, Word, a blog).

As a big fan of free software (which will become more apparent the more I review), I like GeoGebra. If you ever need a little help with those geometry constructions, you can’t find a cheaper solution.