Skip to content

Ensure consistent left/right solution brackets for bracketing solvers #764

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
ChrisRackauckas merged 2 commits into from
Dec 31, 2025
+122 −228
Merged

Ensure consistent left/right solution brackets for bracketing solvers #764

Show file tree
Hide file tree
Changes from 1 commit
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
dc4592f
Ensure consistent left/right solution brackets for bracketing solvers
dcourteville Dec 30, 2025
73eee2e
Remove duplicate bisection implementation and useless calls to it
dcourteville Dec 31, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
2 changes: 1 addition & 1 deletion lib/BracketingNonlinearSolve/Project.toml
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,7 +1,7 @@
name = "BracketingNonlinearSolve"
uuid = "70df07ce-3d50-431d-a3e7-ca6ddb60ac1e"
authors = ["Avik Pal <avikpal@mit.edu> and contributors"]
version = "1.6.1"
version = "1.6.2"

[deps]
CommonSolve = "38540f10-b2f7-11e9-35d8-d573e4eb0ff2"
Expand Down
1 change: 1 addition & 0 deletions lib/BracketingNonlinearSolve/src/BracketingNonlinearSolve.jl
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -10,6 +10,7 @@ using SciMLBase: SciMLBase, IntervalNonlinearProblem, ReturnCode

abstract type AbstractBracketingAlgorithm <: AbstractNonlinearSolveAlgorithm end

include("utils.jl")
include("common.jl")

include("alefeld.jl")
Expand Down
46 changes: 11 additions & 35 deletions lib/BracketingNonlinearSolve/src/alefeld.jl
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -18,15 +18,11 @@ function SciMLBase.__solve(

fc = f(c)
if a == c || b == c
return SciMLBase.build_solution(
prob, alg, c, fc; retcode = ReturnCode.FloatingPointLimit, left = a, right = b
)
return build_bracketing_solution(prob, alg, c, fc, a, b, ReturnCode.FloatingPointLimit)
end

if iszero(fc)
return SciMLBase.build_solution(
prob, alg, c, fc; retcode = ReturnCode.Success, left = a, right = b
)
return build_exact_solution(prob, alg, c, fc, ReturnCode.Success)
end

a, b, d = Impl.bracket(f, a, b, c)
Expand All @@ -46,14 +42,11 @@ function SciMLBase.__solve(

ē, fc = d, f(c)
if a == c || b == c
return SciMLBase.build_solution(
prob, alg, c, fc; retcode = ReturnCode.FloatingPointLimit,
left = a, right = b)
return build_bracketing_solution(prob, alg, c, fc, a, b, ReturnCode.FloatingPointLimit)
end

if iszero(fc)
return SciMLBase.build_solution(
prob, alg, c, fc; retcode = ReturnCode.Success, left = a, right = b)
return build_exact_solution(prob, alg, c, fc, ReturnCode.Success)
end

ā, b̄, d̄ = Impl.bracket(f, a, b, c)
Expand All @@ -71,16 +64,11 @@ function SciMLBase.__solve(
fc = f(c)

if ā == c || b̄ == c
return SciMLBase.build_solution(
prob, alg, c, fc;
retcode = ReturnCode.FloatingPointLimit, left = ā, right = b̄
)
return build_bracketing_solution(prob, alg, c, fc, ā, b̄, ReturnCode.FloatingPointLimit)
end

if iszero(fc)
return SciMLBase.build_solution(
prob, alg, c, fc; retcode = ReturnCode.Success, left = ā, right = b̄
)
return build_exact_solution(prob, alg, c, fc, ReturnCode.Success)
end

ā, b̄, d̄ = Impl.bracket(f, ā, b̄, c)
Expand All @@ -94,16 +82,11 @@ function SciMLBase.__solve(
fc = f(c)

if ā == c || b̄ == c
return SciMLBase.build_solution(
prob, alg, c, fc;
retcode = ReturnCode.FloatingPointLimit, left = ā, right = b̄
)
return build_bracketing_solution(prob, alg, c, fc, ā, b̄, ReturnCode.FloatingPointLimit)
end

if iszero(fc)
return SciMLBase.build_solution(
prob, alg, c, fc; retcode = ReturnCode.Success, left = ā, right = b̄
)
return build_exact_solution(prob, alg, c, fc, ReturnCode.Success)
end

ā, b̄, d = Impl.bracket(f, ā, b̄, c)
Expand All @@ -117,15 +100,10 @@ function SciMLBase.__solve(
fc = f(c)

if ā == c || b̄ == c
return SciMLBase.build_solution(
prob, alg, c, fc;
retcode = ReturnCode.FloatingPointLimit, left = ā, right = b̄
)
return build_bracketing_solution(prob, alg, c, fc, ā, b̄, ReturnCode.FloatingPointLimit)
end
if iszero(fc)
return SciMLBase.build_solution(
prob, alg, c, fc; retcode = ReturnCode.Success, left = ā, right = b̄
)
return build_exact_solution(prob, alg, c, fc, ReturnCode.Success)
end
a, b, d = Impl.bracket(f, ā, b̄, c)
end
Expand All @@ -140,7 +118,5 @@ function SciMLBase.__solve(
fc = f(c)

# Return solution when run out of max iteration
return SciMLBase.build_solution(
prob, alg, c, fc; retcode = ReturnCode.MaxIters, left = a, right = b
)
return build_bracketing_solution(prob, alg, c, fc, a, b, ReturnCode.MaxIters)
end
24 changes: 6 additions & 18 deletions lib/BracketingNonlinearSolve/src/bisection.jl
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -33,41 +33,31 @@ function SciMLBase.__solve(
left, abstol, promote_type(eltype(left), eltype(right)))

if iszero(fl)
return SciMLBase.build_solution(
prob, alg, left, fl; retcode = ReturnCode.ExactSolutionLeft, left, right
)
return build_exact_solution(prob, alg, left, fl, ReturnCode.ExactSolutionLeft)
end

if iszero(fr)
return SciMLBase.build_solution(
prob, alg, right, fr; retcode = ReturnCode.ExactSolutionRight, left, right
)
return build_exact_solution(prob, alg, right, fr, ReturnCode.ExactSolutionRight)
end

if sign(fl) == sign(fr)
@SciMLMessage("The interval is not an enclosing interval, opposite signs at the \
boundaries are required.",
verbose, :non_enclosing_interval)
return SciMLBase.build_solution(
prob, alg, left, fl; retcode = ReturnCode.InitialFailure, left, right
)
return build_bracketing_solution(prob, alg, left, fl, left, right, ReturnCode.InitialFailure)
end

i = 1
while i ≤ maxiters
mid = (left + right) / 2

if mid == left || mid == right
return SciMLBase.build_solution(
prob, alg, left, fl; retcode = ReturnCode.FloatingPointLimit, left, right
)
return build_bracketing_solution(prob, alg, left, fl, left, right, ReturnCode.FloatingPointLimit)
end

fm = f(mid)
if abs((right - left) / 2) < abstol
return SciMLBase.build_solution(
prob, alg, mid, fm; retcode = ReturnCode.Success, left, right
)
return build_bracketing_solution(prob, alg, mid, fm, left, right, ReturnCode.Success)
end

if iszero(fm)
Expand All @@ -93,7 +83,5 @@ function SciMLBase.__solve(

sol !== nothing && return sol

return SciMLBase.build_solution(
prob, alg, left, fl; retcode = ReturnCode.MaxIters, left, right
)
return build_bracketing_solution(prob, alg, left, fl, left, right, ReturnCode.MaxIters)
end
25 changes: 6 additions & 19 deletions lib/BracketingNonlinearSolve/src/brent.jl
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -31,24 +31,18 @@ function SciMLBase.__solve(
)

if iszero(fl)
return SciMLBase.build_solution(
prob, alg, left, fl; retcode = ReturnCode.ExactSolutionLeft, left, right
)
return build_exact_solution(prob, alg, left, fl, ReturnCode.ExactSolutionLeft)
end

if iszero(fr)
return SciMLBase.build_solution(
prob, alg, right, fr; retcode = ReturnCode.ExactSolutionRight, left, right
)
return build_exact_solution(prob, alg, right, fr, ReturnCode.ExactSolutionRight)
end

if sign(fl) == sign(fr)
@SciMLMessage("The interval is not an enclosing interval, opposite signs at the \
boundaries are required.",
verbose, :non_enclosing_interval)
return SciMLBase.build_solution(
prob, alg, left, fl; retcode = ReturnCode.InitialFailure, left, right
)
return build_bracketing_solution(prob, alg, left, fl, left, right, ReturnCode.InitialFailure)
end

if abs(fl) < abs(fr)
Expand Down Expand Up @@ -83,10 +77,7 @@ function SciMLBase.__solve(
# Bisection method
s = (left + right) / 2
if s == left || s == right
return SciMLBase.build_solution(
prob, alg, left, fl;
retcode = ReturnCode.FloatingPointLimit, left, right
)
return build_bracketing_solution(prob, alg, left, fl, left, right, ReturnCode.FloatingPointLimit)
end
cond = true
else
Expand All @@ -95,9 +86,7 @@ function SciMLBase.__solve(

fs = f(s)
if abs((right - left) / 2) < abstol
return SciMLBase.build_solution(
prob, alg, s, fs; retcode = ReturnCode.Success, left, right
)
return build_bracketing_solution(prob, alg, s, fs, left, right, ReturnCode.Success)
end

if iszero(fs)
Expand Down Expand Up @@ -135,7 +124,5 @@ function SciMLBase.__solve(

sol !== nothing && return sol

return SciMLBase.build_solution(
prob, alg, left, fl; retcode = ReturnCode.MaxIters, left, right
)
return build_bracketing_solution(prob, alg, left, fl, left, right, ReturnCode.MaxIters)
end
24 changes: 6 additions & 18 deletions lib/BracketingNonlinearSolve/src/falsi.jl
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -30,32 +30,24 @@ function SciMLBase.__solve(
left, abstol, promote_type(eltype(left), eltype(right)))

if iszero(fl)
return SciMLBase.build_solution(
prob, alg, left, fl; retcode = ReturnCode.ExactSolutionLeft, left, right
)
return build_exact_solution(prob, alg, left, fl, ReturnCode.ExactSolutionLeft)
end

if iszero(fr)
return SciMLBase.build_solution(
prob, alg, right, fr; retcode = ReturnCode.ExactSolutionRight, left, right
)
return build_exact_solution(prob, alg, right, fr, ReturnCode.ExactSolutionRight)
end

if sign(fl) == sign(fr)
@SciMLMessage("The interval is not an enclosing interval, opposite signs at the \
boundaries are required.",
verbose, :non_enclosing_interval)
return SciMLBase.build_solution(
prob, alg, left, fl; retcode = ReturnCode.InitialFailure, left, right
)
return build_bracketing_solution(prob, alg, left, fl, left, right, ReturnCode.InitialFailure)
end

i = 1
while i ≤ maxiters
if Impl.nextfloat_tdir(left, l, r) == right
return SciMLBase.build_solution(
prob, alg, left, fl; left, right, retcode = ReturnCode.FloatingPointLimit
)
return build_bracketing_solution(prob, alg, left, fl, left, right, ReturnCode.FloatingPointLimit)
end

mid = (fr * left - fl * right) / (fr - fl)
Expand All @@ -67,9 +59,7 @@ function SciMLBase.__solve(

fm = f(mid)
if abs((right - left) / 2) < abstol
return SciMLBase.build_solution(
prob, alg, mid, fm; left, right, retcode = ReturnCode.Success
)
return build_bracketing_solution(prob, alg, mid, fm, left, right, ReturnCode.Success)
end

if abs(fm) < abstol
Expand All @@ -93,7 +83,5 @@ function SciMLBase.__solve(

sol !== nothing && return sol

return SciMLBase.build_solution(
prob, alg, left, fl; retcode = ReturnCode.MaxIters, left, right
)
return build_bracketing_solution(prob, alg, left, fl, left, right, ReturnCode.MaxIters)
end
28 changes: 7 additions & 21 deletions lib/BracketingNonlinearSolve/src/itp.jl
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -71,24 +71,18 @@ function SciMLBase.__solve(
)

if iszero(fl)
return SciMLBase.build_solution(
prob, alg, left, fl; retcode = ReturnCode.ExactSolutionLeft, left, right
)
return build_exact_solution(prob, alg, left, fl, ReturnCode.ExactSolutionLeft)
end

if iszero(fr)
return SciMLBase.build_solution(
prob, alg, right, fr; retcode = ReturnCode.ExactSolutionRight, left, right
)
return build_exact_solution(prob, alg, right, fr, ReturnCode.ExactSolutionRight)
end

if sign(fl) == sign(fr)
@SciMLMessage("The interval is not an enclosing interval, opposite signs at the \
boundaries are required.",
verbose, :non_enclosing_interval)
return SciMLBase.build_solution(
prob, alg, left, fl; retcode = ReturnCode.InitialFailure, left, right
)
return build_bracketing_solution(prob, alg, left, fl, left, right, ReturnCode.InitialFailure)
end

ϵ = abstol
Expand Down Expand Up @@ -120,9 +114,7 @@ function SciMLBase.__solve(

xp = ifelse(abs(xt - mid) ≤ r, xt, mid - copysign(r, diff)) # Projection Step
if span < 2ϵ
return SciMLBase.build_solution(
prob, alg, xt, f(xt); retcode = ReturnCode.Success, left, right
)
return build_bracketing_solution(prob, alg, xt, f(xt), left, right, ReturnCode.Success)
end
yp = f(xp)
yps = yp * sign(fr)
Expand All @@ -131,22 +123,16 @@ function SciMLBase.__solve(
elseif yps < T0
left, fl = xp, yp
else
return SciMLBase.build_solution(
prob, alg, xp, yps; retcode = ReturnCode.Success, left, right
)
return build_exact_solution(prob, alg, xp, yps, ReturnCode.Success)
end

i += 1
ϵ_s /= 2

if nextfloat(left) == right
return SciMLBase.build_solution(
prob, alg, right, fr; retcode = ReturnCode.FloatingPointLimit, left, right
)
return build_bracketing_solution(prob, alg, right, fr, left, right, ReturnCode.FloatingPointLimit)
end
end

return SciMLBase.build_solution(
prob, alg, left, fl; retcode = ReturnCode.MaxIters, left, right
)
return build_bracketing_solution(prob, alg, left, fl, left, right, ReturnCode.MaxIters)
end
Loading
Loading