extract_sparse: Extracts the sparse part from a (U,W) graphon mixture
Description
This function extracts the sparse component from a (U,W) mixture graph by
fitting two lines to the unique sorted log degree values. The first line gives
the number of hubs in the sparse part and the remaining line fits the degrees
of the dense part.
Usage
extract_sparse(gr)
Value
a list with the following components:
num_hubs
The number of hubs in the sparse component.
phat
The probability vector of the sparse component. This is also known as the mass partition.