Convolution in the compact normalisation #
This file defines several versions of the discrete convolution of functions with the compact normalisation.
Main declarations #
conv: Discrete convolution of two functions in the compact normalisationdconv: Discrete difference convolution of two functions in the compact normalisationiterConv: Iterated convolution of a function in the compact normalisation
Notation #
f ∗ g: Convolutionf ○ g: Difference convolutionf ∗^ n: Iterated convolution
Notes #
Some lemmas could technically be generalised to a division ring. Doesn't seem very useful given that
the codomain in applications is either ℝ, ℝ≥0 or ℂ.
Similarly we could drop the commutativity assumption on the domain, but this is unneeded at this point in time.
Compact convolution on a finite group.
The value of f ∗ g at a is the average of the value of f b * g c over b + c = a.
Instances For
Compact convolution on a finite group.
The value of f ∗ g at a is the average of the value of f b * g c over b + c = a.
Equations
- «term_∗_» = Lean.ParserDescr.trailingNode `«term_∗_» 71 71 (Lean.ParserDescr.binary `andthen (Lean.ParserDescr.symbol " ∗ ") (Lean.ParserDescr.cat `term 72))
Instances For
Alias of smul_conv.
Alias of conv_smul.
Compact difference convolution on a finite group.
The value of f ∗ g at a is the average of the value of f b * g c over b - c = a.
Equations
Instances For
Compact difference convolution on a finite group.
The value of f ∗ g at a is the average of the value of f b * g c over b - c = a.
Equations
- «term_○_» = Lean.ParserDescr.trailingNode `«term_○_» 71 71 (Lean.ParserDescr.binary `andthen (Lean.ParserDescr.symbol " ○ ") (Lean.ParserDescr.cat `term 72))
Instances For
Alias of smul_dconv.
Alias of dconv_smul.