# EoN.get_PGFDPrime¶

EoN.get_PGFDPrime(Pk)[source]

Given a degree distribution (as a dict) returns the function $$\psi''(x)$$

Pk dict
Pk[k] is the proportion of nodes with degree k.
psiDPrime function
$$\psi''(x) = \sum_k k(k-1)P_k[k] x^{k-2}$$