--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/forward_model/bias.rs Tue Dec 31 09:25:45 2024 -0500 @@ -0,0 +1,110 @@ +/*! +Simple parametric forward model. + */ + +use numeric_literals::replace_float_literals; +use alg_tools::types::{Float, ClosedAdd}; +use alg_tools::mapping::Space; +use alg_tools::direct_product::Pair; +use alg_tools::linops::{Linear, RowOp, ColOp, IdOp, ZeroOp, AXPY}; +use alg_tools::error::DynError; +use alg_tools::norms::{L2, Norm, PairNorm, NormExponent}; +use crate::types::L2Squared; +use crate::measures::RNDM; +use super::{ForwardModel, AdjointProductBoundedBy, AdjointProductPairBoundedBy, LipschitzValues}; +use crate::transport::TransportLipschitz; + +impl<Domain, F, A, E> ForwardModel<Pair<Domain, A::Observable>, F, PairNorm<E, L2, L2>> +for RowOp<A, IdOp<A::Observable>> +where + E : NormExponent, + Domain : Space + Norm<F, E>, + F : Float, + A::Observable : ClosedAdd + Norm<F, L2> + 'static, + A : ForwardModel<Domain, F, E> + 'static +{ + type Observable = A::Observable; + + fn write_observable(&self, b : &Self::Observable, prefix : String) -> DynError { + self.0.write_observable(b, prefix) + } + + /// Returns a zero observable + fn zero_observable(&self) -> Self::Observable { + self.0.zero_observable() + } +} + +#[replace_float_literals(F::cast_from(literal))] +impl<Domain, F, A, D, Z> AdjointProductPairBoundedBy<Pair<Domain, Z>, D, IdOp<Z>> +for RowOp<A, IdOp<Z>> +where + Domain : Space, + F : Float, + Z : Clone + Space + ClosedAdd, + A : AdjointProductBoundedBy<Domain, D, FloatType=F, Codomain = Z>, + D : Linear<Domain>, + A::Codomain : ClosedAdd, +{ + type FloatType = F; + + fn adjoint_product_pair_bound(&self, d : &D, _ : &IdOp<Z>) -> Option<(F, F)> { + self.0.adjoint_product_bound(d).map(|l_0| { + // [A_*; B_*][A, B] = [A_*A, A_* B; B_* A, B_* B] ≤ diag(2A_*A, 2B_*B) + // ≤ diag(2l_A𝒟_A, 2l_B𝒟_B), where now 𝒟_B=Id and l_B=1. + (2.0 * l_0, 2.0) + }) + } +} + +/// This `impl` is bit of an abuse as the codomain of `Apre` is a [`Pair`] of a measure predual, +/// to which this `impl` applies, and another space. +impl<F, Apre, Z> LipschitzValues +for ColOp<Apre, IdOp<Z>> +where + F : Float, + Z : Clone + Space + ClosedAdd, + Apre : LipschitzValues<FloatType = F>, +{ + type FloatType = F; + /// Return (if one exists) a factor $L$ such that $A_*z$ is $L$-Lipschitz for all + /// $z$ in the unit ball. + fn value_unit_lipschitz_factor(&self) -> Option<Self::FloatType> { + self.0.value_unit_lipschitz_factor() + } + + /// Return (if one exists) a factor $L$ such that $∇A_*z$ is $L$-Lipschitz for all + /// $z$ in the unit ball. + fn value_diff_unit_lipschitz_factor(&self) -> Option<Self::FloatType> { + self.0.value_diff_unit_lipschitz_factor() + } +} + + + +impl<'a, F : Float, Y : Space, XD, const N : usize> TransportLipschitz<L2Squared> for +ZeroOp<'a, RNDM<F, N>, XD, Y, F> { + type FloatType = F; + + fn transport_lipschitz_factor(&self, _ : L2Squared) -> Self::FloatType { + F::ZERO + } +} + + +/// TODO: should assume `D` to be positive semi-definite and self-adjoint. +#[replace_float_literals(F::cast_from(literal))] +impl<'a, F, D, XD, Y, const N : usize> AdjointProductBoundedBy<RNDM<F, N>, D> +for ZeroOp<'a, RNDM<F, N>, XD, Y, F> +where + F : Float, + Y : AXPY<F> + Clone, + D : Linear<RNDM<F, N>>, +{ + type FloatType = F; + /// Return $L$ such that $A_*A ≤ L𝒟$ is bounded by some `other` operator $𝒟$. + fn adjoint_product_bound(&self, _ : &D) -> Option<F> { + Some(0.0) + } +} +