While we've only covered two types of generative model, there are many different types that you may encounter in the literature. The following chart is not exhaustive, but does provide a general overview of the types of generative models out there:
Let's break this down:
- Explicit density models: Model our data directly from a probability distribution. We explicitly define the probability and solve for it
- Implicit density models: Learn to sample from a probability distribution without defining what that distribution is
Within explicit density models, we have tractable density models and approximate density models. Here, tractable is related to defined computational time; we can calculate the computational complexity of a tractable problem. Approximate density relates to intractability—a computer science term that means that...