J Lawson


Quiver computations

Throughout my PhD I developed a suite of tools to compute mutations of quivers. More information on the uses of these tools can be found on the maths page, with more complete information on the quiver software page.

The main library containing most of the computations, data structures and graph objects.
Tool to generate all mutation-finite quivers of a given size.
All subquivers of a mutation-finite quiver must also be mutation-finite, so candidates for mutation-finite quivers of a given size can be constructed by adding a vertex to all smaller mutation-finite quivers. The size of each candidate’s mutation class can then be computed to determine whether it is finite or not. As a single vertex quiver’s mutation class only contains itself we can recursively compute all mutation-finite quivers of any size.
MPI based parallel executable to compute every minimally mutation-infinite quiver.
A minimally mutation-infinite quiver is a quiver which is mutation-infinite, but every subquiver is mutation-finite. There are many possible candidates so a parallel method to check many quivers simultaneously scaled well across many cores.
A CLI tool to filter streams of quivers.
Tools such as qvmmi and qvfin generate large text streams containing representations of quivers. Due to the design and parallel nature of these programs these streams will typically contain duplicates and quivers which are identical up to permutation of their vertices. The qvtrim tools allows a user to filter these streams to only show quivers that are useful to them.
Tools to draw quivers, exchange graphs and mutation classes
As quivers can be represented as directed graphs, and their exchange graphs have interesting geometric properties is it useful to be able to visualise them. The tools in qvdraw can layout the graph and output as a picture or as LaTeX to allow images to be embedded in papers.

N-of-1 trial app

In the summer of 2012 I developed a proof of concept Android app to aid clinicians running N-of-1 trials. The project has now ended and the software is no longer maintained, but the source is still available on Github.

Ludum Dare

I have participated in a number of the game creation competitions Ludum Dare. Write ups for these are on the Ludum Dare page.