Getting the algorithm behind the pos routine in matlab?

I're my guiding Implementing RCM - Reverse Cuthill McKee. We believe that with a slight modification of the method becomes more effective. But we need to know how the method was implemented to really know if what we are proposing is something new.

Answer 1

[José-Luis]

I will guess that you are talking about symrcm(). It is a built-in Matlab function. Here is what the documentation says:

The algorithm first finds a pseudoperipheral vertex of the graph of the matrix. It then generates a level structure by breadth-first search and orders the vertices by decreasing distance from the pseudoperipheral vertex. The implementation is based closely on the SPARSPAK implementation described by George and Liu.

If you want/need more than that you need to ask the Mathworks, but I very much doubt they will let you have the source code.