alg_tools: comparison src/convex.rs

-:9226980e45a7
+:848ecc05becf
 /*!
 Some convex analysis basics
 */
+use std::marker::PhantomData;
 use crate::types::*;
 use crate::mapping::{Mapping, Space};
+use crate::linops::IdOp;
 use crate::instance::{Instance, InstanceMut, DecompositionMut};
 use crate::norms::*;
 /// Trait for convex mappings. Has no features, just serves as a constraint
 ///
 /// TODO: should constrain `Mapping::Codomain` to implement a partial order,
 /// but this makes everything complicated with little benefit.
-pub trait ConvexMapping<Domain : Space> : Mapping<Domain>
+pub trait ConvexMapping<Domain : Space, F : Num = f64> : Mapping<Domain, Codomain = F>
 {}
 /// Trait for mappings with a Fenchel conjugate
 ///
 /// The conjugate type has to implement [`ConvexMapping`], but a `Conjugable` mapping need
 /// not be convex.
-pub trait Conjugable<Domain : Space> : Mapping<Domain> {
+pub trait Conjugable<Domain : HasDual<F>, F : Num = f64> : Mapping<Domain> {
-type DualDomain : Space;
+type Conjugate<'a> : ConvexMapping<Domain::DualSpace, F> where Self : 'a;
-type Conjugate<'a> : ConvexMapping<Self::DualDomain> where Self : 'a;
 fn conjugate(&self) -> Self::Conjugate<'_>;
 }
 /// Trait for mappings with a Fenchel preconjugate
 ///
 /// In contrast to [`Conjugable`], the preconjugate need not implement [`ConvexMapping`],
-/// but a `Preconjugable` mapping has be convex.
+/// but a `Preconjugable` mapping has to be convex.
-pub trait Preconjugable<Domain : Space> : ConvexMapping<Domain> {
+pub trait Preconjugable<Domain, Predual, F : Num = f64> : ConvexMapping<Domain, F>
-type PredualDomain : Space;
+where
-type Preconjugate<'a> : Mapping<Self::PredualDomain> where Self : 'a;
+Domain : Space,
+Predual : HasDual<F>
+{
+type Preconjugate<'a> : Mapping<Predual> where Self : 'a;
 fn preconjugate(&self) -> Self::Preconjugate<'_>;
 }
 /// Trait for mappings with a proximap map
 }
 pub struct NormConjugate<F : Float, E : NormExponent>(NormMapping<F, E>);
-impl<Domain, E, F> ConvexMapping<Domain> for NormMapping<F, E>
+impl<Domain, E, F> ConvexMapping<Domain, F> for NormMapping<F, E>
 where
 Domain : Space,
 E : NormExponent,
 F : Float,
-Self : Mapping<Domain, Codomain=F> {}
+Self : Mapping<Domain, Codomain=F>
+{}
-impl<Domain, E, F> ConvexMapping<Domain> for NormConjugate<F, E>
-where
-Domain : Space,
-E : NormExponent,
-F : Float,
-Self : Mapping<Domain, Codomain=F> {}
 impl<F, E, Domain> Mapping<Domain> for NormConjugate<F, E>
 where
 Domain : Space + Norm<F, E>,
 F::INFINITY
 }
 }
 }
+impl<Domain, E, F> ConvexMapping<Domain, F> for NormConjugate<F, E>
+where
-impl<E, F, Domain> Conjugable<Domain> for NormMapping<F, E>
+Domain : Space,
-where
+E : NormExponent,
-E : NormExponent + Clone,
+F : Float,
-F : Float,
+Self : Mapping<Domain, Codomain=F>
-Domain : Norm<F, E> + Space,
+{}
-{
-type DualDomain = Domain;
+impl<E, F, Domain> Conjugable<Domain, F> for NormMapping<F, E>
-type Conjugate<'a> = NormConjugate<F, E> where Self : 'a;
+where
+E : HasDualExponent,
+F : Float,
+Domain : HasDual<F> + Norm<F, E> + Space,
+<Domain as HasDual<F>>::DualSpace : Norm<F, E::DualExp>
+{
+type Conjugate<'a> = NormConjugate<F, E::DualExp> where Self : 'a;
 fn conjugate(&self) -> Self::Conjugate<'_> {
-NormConjugate(self.clone())
+NormConjugate(self.exponent.dual_exponent().as_mapping())
 }
 }
+/// The zero mapping
+pub struct Zero<Domain : Space, F : Num>(PhantomData<(Domain, F)>);
+impl<Domain : Space, F : Num> Zero<Domain, F> {
+pub fn new() -> Self {
+Zero(PhantomData)
+}
+}
+impl<Domain : Space, F : Num> Mapping<Domain> for Zero<Domain, F> {
+type Codomain = F;
+/// Compute the value of `self` at `x`.
+fn apply<I : Instance<Domain>>(&self, _x : I) -> Self::Codomain {
+F::ZERO
+}
+}
+impl<Domain : Space, F : Num> ConvexMapping<Domain, F> for Zero<Domain, F> { }
+impl<Domain : HasDual<F>, F : Float> Conjugable<Domain, F> for Zero<Domain, F> {
+type Conjugate<'a> = ZeroIndicator<Domain::DualSpace, F> where Self : 'a;
+#[inline]
+fn conjugate(&self) -> Self::Conjugate<'_> {
+ZeroIndicator::new()
+}
+}
+impl<Domain, Predual, F : Float> Preconjugable<Domain, Predual, F> for Zero<Domain, F>
+where
+Domain : Space,
+Predual : HasDual<F>
+{
+type Preconjugate<'a> = ZeroIndicator<Predual, F> where Self : 'a;
+#[inline]
+fn preconjugate(&self) -> Self::Preconjugate<'_> {
+ZeroIndicator::new()
+}
+}
+impl<Domain : Space + Clone, F : Num> Prox<Domain> for Zero<Domain, F> {
+type Prox<'a> = IdOp<Domain> where Self : 'a;
+#[inline]
+fn prox_mapping(&self, _τ : Self::Codomain) -> Self::Prox<'_> {
+IdOp::new()
+}
+}
+/// The zero indicator
+pub struct ZeroIndicator<Domain : Space, F : Num>(PhantomData<(Domain, F)>);
+impl<Domain : Space, F : Num> ZeroIndicator<Domain, F> {
+pub fn new() -> Self {
+ZeroIndicator(PhantomData)
+}
+}
+impl<Domain : Normed<F>, F : Float> Mapping<Domain> for ZeroIndicator<Domain, F> {
+type Codomain = F;
+/// Compute the value of `self` at `x`.
+fn apply<I : Instance<Domain>>(&self, x : I) -> Self::Codomain {
+x.eval(|x̃| if x̃.is_zero() { F::ZERO } else { F::INFINITY })
+}
+}
+impl<Domain : Normed<F>, F : Float> ConvexMapping<Domain, F> for ZeroIndicator<Domain, F> { }
+impl<Domain : HasDual<F>, F : Float> Conjugable<Domain, F> for ZeroIndicator<Domain, F> {
+type Conjugate<'a> = Zero<Domain::DualSpace, F> where Self : 'a;
+#[inline]
+fn conjugate(&self) -> Self::Conjugate<'_> {
+Zero::new()
+}
+}
+impl<Domain, Predual, F : Float> Preconjugable<Domain, Predual, F> for ZeroIndicator<Domain, F>
+where
+Domain : Normed<F>,
+Predual : HasDual<F>
+{
+type Preconjugate<'a> = Zero<Predual, F> where Self : 'a;
+#[inline]
+fn preconjugate(&self) -> Self::Preconjugate<'_> {
+Zero::new()
+}
+}

Mercurial > repos > alg_tools / file comparison

comparison: src/convex.rs

src/convex.rs