I am refreshing my memory on C# (first used it several years ago), and I want to look at some real world quality code (rather than the simplistic ones used in many books).
My preference would be mathematical/statistics libraries written in C# as I would like to see how Matrices and PDEs (partial differential equations etc) are implemented in C#.
Can anyone recommend a good quality online resource where I can view some 'industrial grade' preferably (Math/Stats) library/application written in C#?