node & edge "binning"

[cassinius]

I many algorithms, we check for all possible combinations of edges or nodes, even though only the immediate neighborhood contains interesting objects.

• define a neighborhood metric
• bin nodes / edges according to neighborhood
• measure the acceleration

[cassinius]

• for triad count, introduce a measure of self-connectedness that is not too weird (self_in_degree, self_out, self_conn... !?)
• maybe a graph projection that eliminates self-loops, or an option in an input-class which does it...?