I’m supposed to be doing the final edits on the journal version of this old paper of mine (jointly with Greg Sorkin and David Gamarnik), but I’ve thought of a way to procrastinate.
Instead of checking the proofs that the length of the shortest path in my weigthed width-2 strip is 
from pylab import *
from networkx import *
G = Graph()
for u, v in grid_2d_graph(100, 2).edges():
G.add_edge(u, v, weight=rand() < .5)
wt, p = bidirectional_dijkstra(G, (0,0), (99,1))
Filed under combinatorial optimization
I re-read a short paper of Andrew Gelman’s yesterday about multilevel modeling, and thought “That would make a nice example for PyMC”. The paper is “Multilevel (hierarchical) modeling: what it can and cannot do, and R code for it is on his website.
To make things even easier for a casual blogger like myself, the example from the paper is extended in the “ARM book”, and Whit Armstrong has already implemented several variants from this book in PyMC. Continue reading
Filed under MCMC, statistics
Healthy Algorithms 