module Piecewise_linear: Piecewise_linear
piece-wise linear interpolation from float-like types to float
module type S = Piecewise_linear_intf.S
module type S_invertible = Piecewise_linear_intf.S_invertible
module Make: 
module Make_invertible: 
module Time: S  with type key = Time.t   with type value = float
module Ofday: S  with type key = Ofday.t  with type value = float
module Span: S  with type key = Span.t   with type value = float
module Float: S  with type key = float    with type value = float
module Int: S  with type key = int      with type value = float