Do not create child node if the start point is not domain feasible. (#…

…199)

* Don't create child node if the domain oracle is infeasible.

* Set version up after bug fix.

* Apply suggestions from code review

* Print statement in case assert fails.

* Print logs for better bug hunting.

* Another try to reproduce error.

* Test lower bound against tree.incumbent plus current fw_epsilon.

* Have the same seed as in runtests.jl.

---------

Co-authored-by: Hendrych <[email protected]>
Co-authored-by: Mathieu Besançon <[email protected]>

Project.toml

@@ -1,7 +1,7 @@
 name = "Boscia"
 uuid = "36b166db-dac5-4d05-b36a-e6c4cef071c9"
 authors = ["ZIB IOL"]
-version = "0.1.27"
+version = "0.1.28"
 
 [deps]
 Bonobo = "f7b14807-3d4d-461a-888a-05dd4bca8bc3"

src/interface.jl

@@ -642,7 +642,8 @@ function postsolve(tree, result, time_ref, verbose, max_iteration_post)
             else
                 @info "primal >= tree.incumbent"
                 @assert primal <= tree.incumbent + 1e-3 ||
-                        isapprox(primal, tree.incumbent, atol=1e-6, rtol=1e-2)
+                        isapprox(primal, tree.incumbent, atol=1e-6, rtol=1e-2) "primal <= tree.incumbent + 1e-3 ||
+                        isapprox(primal, tree.incumbent, atol=1e-6, rtol=1e-2): primal=$(primal) and tree.incumbent=$(tree.incumbent)"
             end
             @info "postsolve did not improve the solution"
             primal = tree.incumbent_solution.objective = tree.solutions[1].objective

src/node.jl

@@ -161,15 +161,18 @@ function Bonobo.get_branching_nodes_info(tree::Bonobo.BnBTree, node::FrankWolfeN
     x_right = FrankWolfe.compute_active_set_iterate!(active_set_right)
     domain_oracle = tree.root.options[:domain_oracle]
 
-    nodes = if !prune_left && !prune_right
+    domain_right = domain_oracle(x_right)
+    domain_left = domain_oracle(x_left)
+
+    nodes = if !prune_left && !prune_right && domain_right && domain_left
         [node_info_left, node_info_right]
     elseif prune_left
         [node_info_right]
     elseif prune_right
         [node_info_left]
-    elseif domain_oracle(x_right)
+    elseif domain_right # x_right in domain
         [node_info_right]
-    elseif domain_oracle(x_left)
+    elseif domain_left # x_left in domain
         [node_info_left]
     else
         warn("No childern nodes can be created.")
@@ -320,7 +323,7 @@ function Bonobo.evaluate_node!(tree::Bonobo.BnBTree, node::FrankWolfeNode)
     elseif node.id == 1
         @debug "Lower bound of root node: $(lower_bound)"
         @debug "Current incumbent: $(tree.incumbent)"
-        @assert lower_bound <= tree.incumbent + 1e-5 "lower_bound <= tree.incumbent + 1e-5 : $(lower_bound) <= $(tree.incumbent + 1e-5)"
+        @assert lower_bound <= tree.incumbent + node.fw_dual_gap_limit "lower_bound <= tree.incumbent + node.fw_dual_gap_limit : $(lower_bound) <= $(tree.incumbent + node.fw_dual_gap_limit)"
     end
 
     # Call heuristic 

test/heuristics.jl

@@ -159,7 +159,7 @@ diffi = x_sol + 0.3 * dir
     heu = Boscia.Heuristic(Boscia.probability_rounding, 0.6, :probability_rounding)
 
     x, _, result =
-        Boscia.solve(f, grad!, sblmo, fill(0.0, m), fill(1.0, m), int_vars, n, custom_heuristics=[heu], rounding_prob=0.0)
+        Boscia.solve(f, grad!, sblmo, fill(0.0, m), fill(1.0, m), int_vars, n, custom_heuristics=[heu], rounding_prob=0.0, verbose=false)
 
     @test f(x) ≥ f(x_sol)
     if isapprox(sum(x_sol), N)