The function calculates Shannon's Entropy. The function is
meant for internal use only. To calculate the entropy for each action in the
design, please use the wrapper function
calc_entropy(design, priors = NULL)
A matrix with rows equal to the number of rules and columns equal to the number of actions or a list of such matrices.
A vector of prior values. If the design is a list of matrices, priors can be a matrix with rows equal to the length of the design and columns equal to the number of rules.
Returns a vector of entropies for each possible action with the following attributes: