My research interests at the present time are in the area of classification of combinatorial designs of various different sorts, including Hadamard mareices, 2-designs, Two-graphs, strongly regular graphs and cospectral graphs. In some cases I have been able to classify the designs completely and where this has been possible I have stored the designs on disc. They can be accessed via the links in the side-bar on the left . These files will be updated at intervals, as I find the time.

Recently, along with Andries Brouwer [1], I have extended some of the results that Willem Haemers and I obtained concerning cospectral graphs [2]. In that paper Haemers and I considered graphs with

All the results of [2] have now been extended to the case

The details of the data for all these different spectra may be found by accessing the appropriate link on the sidebar on the left-hand side of the page.

[1] A. E. Brouwer and E Spence, Cospectral graphs on 12 vertices,

[2] W. H. Haemers, E. Spence, Enumeration of cospectral graphs,