In mathematics, the ε-covering number of a metric space (X, d), for some ε > 0, is the minimum number of balls of radius that are needed to cover X.
A related concept is the ε-packing number which is defined as the maximum number of disjoint balls of radius ε that fit into X.
Famous quotes containing the words covering and/or number:
“You had to have seen the corpses lying there in front of the school—the men with their caps covering their faces—to know the meaning of class hatred and the spirit of revenge.”
—Alfred Döblin (1878–1957)
“Not too many years ago, a child’s experience was limited by how far he or she could ride a bicycle or by the physical boundaries that parents set. Today ... the real boundaries of a child’s life are set more by the number of available cable channels and videotapes, by the simulated reality of videogames, by the number of megabytes of memory in the home computer. Now kids can go anywhere, as long as they stay inside the electronic bubble.”
—Richard Louv (20th century)