add kwarg is_feasible_error to interior_point_Newton

Author: JoshuaLampert

Changelog.md

@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+* add keyword argument `is_feasible_error` to `interior_point_Newton` to control how to handle infeasible starting points (#556)
 * add keyword argument `at_init` to some debug options to control whether they print already at the initialisation and hence before the first iteration (#552)
 
 ## [0.5.29] November 26, 2025

src/plans/interior_point_Newton_plan.jl

@@ -93,6 +93,7 @@ $(_var(:Keyword, :retraction_method))
 * `step_state`: the [`StepsizeState`](@ref) with point and search direction
 $(_var(:Keyword, :stepsize; default = "[`ArmijoLinesearch`](@ref)`()`", add = " with the [`InteriorPointCentralityCondition`](@ref) as
   additional condition to accept a step"))
+* `is_feasible_error=:error`: specify how to handle infeasible starting points, see [`is_feasible`](@ref) for options.
 
 and internally `_step_M` and `_step_p` for the manifold and point in the stepsize.
 """
@@ -126,6 +127,7 @@ mutable struct InteriorPointNewtonState{
     stepsize::TStepsize
     step_problem::TStepPr
     step_state::TStepSt
+    is_feasible_error::Symbol
     function InteriorPointNewtonState(
             M::AbstractManifold,
             cmo::ConstrainedManifoldObjective,
@@ -161,6 +163,7 @@ mutable struct InteriorPointNewtonState{
                 initial_stepsize = 1.0,
                 additional_decrease_condition = centrality_condition,
             ),
+            is_feasible_error::Symbol = :error,
             kwargs...,
         ) where {
             P,
@@ -194,6 +197,7 @@ mutable struct InteriorPointNewtonState{
         ips.stepsize = stepsize
         ips.step_problem = step_problem
         ips.step_state = step_state
+        ips.is_feasible_error = is_feasible_error
         return ips
     end
 end

src/solvers/interior_point_Newton.jl

@@ -93,6 +93,7 @@ $(_var(:Keyword, :sub_state; default = "[`ConjugateResidualState`](@ref)"))
 * `Y=zero(μ)`:  the initial gradient with respect to `μ`
 * `Z=zero(λ)`:  the initial gradient with respect to `λ`
 * `W=zero(s)`:  the initial gradient with respect to `s`
+* `is_feasible_error=:error`:  specify how to handle infeasible starting points, see [`is_feasible`](@ref) for options.
 
 As well as internal keywords used to set up these given keywords like `_step_M`, `_step_p`, `_sub_M`, `_sub_p`, and `_sub_X`,
 that should not be changed.
@@ -234,13 +235,14 @@ function interior_point_Newton!(
             sub_kwargs...,
         ),
         sub_problem::Pr = DefaultManoptProblem(TangentSpace(_sub_M, _sub_p), sub_objective),
+        is_feasible_error = :error,
         kwargs...,
     ) where {
         O <: Union{ConstrainedManifoldObjective, AbstractDecoratedManifoldObjective},
         St <: AbstractManoptSolverState,
         Pr <: Union{F, AbstractManoptProblem} where {F},
     }
-    !is_feasible(M, cmo, p; error = :error)
+    !is_feasible(M, cmo, p; error = is_feasible_error)
     keywords_accepted(interior_point_Newton!; kwargs...)
     dcmo = decorate_objective!(M, cmo; kwargs...)
     dmp = DefaultManoptProblem(M, dcmo)
@@ -251,6 +253,7 @@ function interior_point_Newton!(
         retraction_method = retraction_method,
         step_problem = step_problem, step_state = step_state,
         stepsize = _produce_type(stepsize, _step_M),
+        is_feasible_error = is_feasible_error,
         kwargs...,
     )
     ips = decorate_state!(ips; kwargs...)
@@ -262,7 +265,7 @@ calls_with_kwargs(::typeof(interior_point_Newton!)) = (decorate_objective!, deco
 function initialize_solver!(amp::AbstractManoptProblem, ips::InteriorPointNewtonState)
     M = get_manifold(amp)
     cmo = get_objective(amp)
-    !is_feasible(M, cmo, ips.p; error = :error)
+    !is_feasible(M, cmo, ips.p; error = ips.is_feasible_error)
     return ips
 end