EECS20N: Signals and Systems

Syntax (summary)

  • f, g, h, Score, … names of functions
  • f : X → Y, X = domain( f ), Y = range( f )
  • Function definitions using tables and graphs
  • [X → Y], set of all functions from X into Y, is a function space.
  • A system is a function on function spaces: s: [X → Y] →  [W → Z].
Warning A function f is different from its value f(x) at a point x. So it is incorrect to write something like: "let f(x) be a function". Also, the information carried by a signal is contained in the whole function and not in its value at one point.