comparison: src/convex.rs
src/convex.rs
- branch
- dev
- changeset 108
- 6be459f08b66
- parent 107
- 441d30e66a4a
- child 109
- 943c6b3b9414
equal
deleted
inserted
replaced
| 107:441d30e66a4a | 108:6be459f08b66 |
|---|---|
| 14 | 14 |
| 15 /// Trait for convex mappings. Has no features, just serves as a constraint | 15 /// Trait for convex mappings. Has no features, just serves as a constraint |
| 16 /// | 16 /// |
| 17 /// TODO: should constrain `Mapping::Codomain` to implement a partial order, | 17 /// TODO: should constrain `Mapping::Codomain` to implement a partial order, |
| 18 /// but this makes everything complicated with little benefit. | 18 /// but this makes everything complicated with little benefit. |
| 19 pub trait ConvexMapping<Domain: Space, F: Num = f64>: Mapping<Domain, Codomain = F> {} | 19 pub trait ConvexMapping<Domain: Space, F: Num = f64>: Mapping<Domain, Codomain = F> { |
| 20 /// Returns (a lower estimate of) the factor of strong convexity. | |
| 21 /// | |
| 22 /// TODO: should include a specification of the respective norm. | |
| 23 fn factor_of_strong_convexity(&self) -> F { | |
| 24 F::ZERO | |
| 25 } | |
| 26 } | |
| 20 | 27 |
| 21 /// Trait for mappings with a Fenchel conjugate | 28 /// Trait for mappings with a Fenchel conjugate |
| 22 /// | 29 /// |
| 23 /// The conjugate type has to implement [`ConvexMapping`], but a `Conjugable` mapping need | 30 /// The conjugate type has to implement [`ConvexMapping`], but a `Conjugable` mapping need |
| 24 /// not be convex. | 31 /// not be convex. |
| 291 fn apply<I: Instance<Domain>>(&self, x: I) -> Self::Codomain { | 298 fn apply<I: Instance<Domain>>(&self, x: I) -> Self::Codomain { |
| 292 x.eval(|x̃| if x̃.is_zero() { F::ZERO } else { F::INFINITY }) | 299 x.eval(|x̃| if x̃.is_zero() { F::ZERO } else { F::INFINITY }) |
| 293 } | 300 } |
| 294 } | 301 } |
| 295 | 302 |
| 296 impl<Domain: Normed<F>, F: Float> ConvexMapping<Domain, F> for ZeroIndicator<Domain, F> {} | 303 impl<Domain: Normed<F>, F: Float> ConvexMapping<Domain, F> for ZeroIndicator<Domain, F> { |
| 304 fn factor_of_strong_convexity(&self) -> F { | |
| 305 F::INFINITY | |
| 306 } | |
| 307 } | |
| 297 | 308 |
| 298 impl<Domain: HasDual<F>, F: Float> Conjugable<Domain, F> for ZeroIndicator<Domain, F> { | 309 impl<Domain: HasDual<F>, F: Float> Conjugable<Domain, F> for ZeroIndicator<Domain, F> { |
| 299 type Conjugate<'a> | 310 type Conjugate<'a> |
| 300 = Zero<Domain::DualSpace, F> | 311 = Zero<Domain::DualSpace, F> |
| 301 where | 312 where |
| 340 fn apply<I: Instance<Domain>>(&self, x: I) -> Self::Codomain { | 351 fn apply<I: Instance<Domain>>(&self, x: I) -> Self::Codomain { |
| 341 x.eval(|z| z.norm2_squared() / F::TWO) | 352 x.eval(|z| z.norm2_squared() / F::TWO) |
| 342 } | 353 } |
| 343 } | 354 } |
| 344 | 355 |
| 345 impl<Domain: Euclidean<F>, F: Float> ConvexMapping<Domain, F> for Norm222<F> {} | 356 impl<Domain: Euclidean<F>, F: Float> ConvexMapping<Domain, F> for Norm222<F> { |
| 357 fn factor_of_strong_convexity(&self) -> F { | |
| 358 F::ONE | |
| 359 } | |
| 360 } | |
| 346 | 361 |
| 347 impl<Domain: Euclidean<F>, F: Float> Conjugable<Domain, F> for Norm222<F> { | 362 impl<Domain: Euclidean<F>, F: Float> Conjugable<Domain, F> for Norm222<F> { |
| 348 type Conjugate<'a> | 363 type Conjugate<'a> |
| 349 = Self | 364 = Self |
| 350 where | 365 where |
