RBMs in Morb

In Morb, an RBM is defined by specifying a set of units and a set of parameters. The units represent the random variables that are being modelled. In an RBM, some of these will be observed and some will be latent, but this distinction is not made when it is not necessary (in practice: only during training). The parameters define relations between the units, by specifying potentials that are added to the energy function of the RBM. Potentials that are high (low) for a particular configuration of units will increase (decrease) the energy of this configuration, and thus make it less likely.

Units are represented by instances of the Units class. Different types of units correspond to different subclasses of Units. Essentially, a type of units defines two things:

• the domain of the values that these units can assume (discrete, continuous on [0, 1], continuous and positive, ...)
• the distribution across this domain (bernoulli, gaussian, exponential, ...)