ABSTRACT
Knowing how to visualize compositional data is particularly helpful in understanding and interpreting their properties. The fixed sum constraint on compositional data leads to a special geometric representation of compositions in a space called a simplex. The simplest form of a simplex is a triangle, which contains three-part compositions. Four-part compositions are contained in a three-dimensional tetrahedron. Higher-dimensional simplexes, which cannot be visualized directly, contain compositions with more than four parts. In this chapter several ways of displaying compositional data are considered.
