# Tag: graph theory

# Graph editor and Matrix generator

Making matrix representations of graphs always takes a lot of time. For practicing algebraic or spectral graph theory on computer algebra systems, one has to create a lot of graphs. A handy tool can make this easy, which allows to draw graphs and generate code e.g. for Maple with one click. Well I couldn’t find a tool like that, so I made one on the weekend in C#. With it, you can draw custom graphs, including: arbitrary loops, parallel edges, directed edges, etc. and can generate code for these computer algebra systems: Maple, MATLAB, Maxima. Then the code can be

# An interesting proof of Turán’s theorem

In the past few days I have been reading a nice book about graph theory, including solving the exercises in it. Once I encountered an exercise which I couldn’t solve, so made a little research, and found that the solution is the proof of the Turán’s theorem. The usual proof for this theorem is built on induction, but later I have found a proof which is using a basic inequality. I am sure that I’m not the first one who have seen this solution, although I couldn’t find it on the net yet.