Chapter 7
Mixture Models
...the father has the form of a lion, the mother of an ant; the father eats flesh and the mother herbs. And these breed the ant-lion... –The Book of Imaginary Beings
The River Plate (also known as La Plata River or Río de la Plata) is the widest river on Earth and a natural border between Argentina and Uruguay. During the late 19th century, the port area along this river was a place where indigenous people mixed with Africans (most of them slaves) and European immigrants. One consequence of this encounter was the mix of European music, such as the waltz and mazurka, with the African candombe and Argentinian milonga (which, in turn, is a mix of Afro-American rhythms), giving origin to the dance and music we now call the tango.
Mixing previously existing elements is a great way to create new things, not only in the context of music. In statistics, mixture models are one common approach to model building. These models are built by mixing simpler...