function f = FitnessFuncMet(cb, p, met)
%Fitness(cb,p) - Returns the fitness of a given codebook cb with priors p.
%
% The fitness calculated is a lower bound on the mutual information assuming multiplicative covariant Gaussian noise.
% The codebook is an N by M matrix, where N is the number of neurons and M is the number of symbols.
% P is a vector of length M. Met is the metabolic weighting constant.
f = FitnessFunc(cb,p) - met*p'*sum(cb,2);