ParticleSwarm: clamp c2 to 3/2 when it falls below 3/2 by inayatku · Pull Request #1294 · JuliaNLSolvers/Optim.jl

inayatku · 2026-10-17T18:22:19Z

update_swarm_params! clamps the coefficients c1 and c2 to [3/2, 5/2]. For c1 a value below 3/2 is set to 3/2, but for c2 it was set to 5/2. So whenever c2 fell below 3/2 (it decreases in states 1, 2 and 4), it jumped to the upper end, and the rescaling for c1 + c2 > 4 then also lowered c1.

This sets c2 to 3/2, as for c1.

New test: starting from c1 = c2 = 3/2, states 1 and 4 must leave c2 at 3/2. On master the test gives c2 = 2.46 and c2 = 2.5. The particle swarm tests pass (10 of 10).

github-actions · 2026-10-17T18:28:49Z

Benchmark Results (Julia vlts)

Time benchmarks

	master	`1976c6b`...	master / `1976c6b`...
multivariate/problems/rosenbrock/100/KrylovTrustRegion	0.164 ± 0.0076 ms	0.164 ± 0.0068 ms	0.999 ± 0.062
multivariate/problems/rosenbrock/100/Newton	0.819 ± 0.037 ms	0.806 ± 0.025 ms	1.02 ± 0.055
multivariate/problems/rosenbrock/100/NewtonTrustRegion	4 ± 0.19 ms	3.92 ± 0.28 ms	1.02 ± 0.087
multivariate/problems/rosenbrock/2/KrylovTrustRegion	14.1 ± 0.64 μs	14.2 ± 0.66 μs	0.997 ± 0.065
multivariate/problems/rosenbrock/2/Newton	18.9 ± 0.63 μs	20.1 ± 0.67 μs	0.943 ± 0.045
multivariate/problems/rosenbrock/2/NewtonTrustRegion	25.6 ± 1.2 μs	26.2 ± 1.3 μs	0.979 ± 0.068
multivariate/problems/rosenbrock/20/KrylovTrustRegion	0.036 ± 0.00099 ms	0.036 ± 0.0016 ms	1 ± 0.053
multivariate/problems/rosenbrock/20/Newton	0.0727 ± 0.0023 ms	0.074 ± 0.0015 ms	0.982 ± 0.037
multivariate/problems/rosenbrock/20/NewtonTrustRegion	0.235 ± 0.0092 ms	0.24 ± 0.0084 ms	0.981 ± 0.051
multivariate/problems/saddle/100/KrylovTrustRegion	0.06 ± 0.0031 ms	0.0613 ± 0.0016 ms	0.979 ± 0.056
multivariate/problems/saddle/100/Newton	0.156 ± 0.0038 ms	0.168 ± 0.0063 ms	0.927 ± 0.042
multivariate/problems/saddle/100/NewtonTrustRegion	2.07 ± 0.067 ms	2.12 ± 0.051 ms	0.98 ± 0.039
multivariate/problems/saddle/2/KrylovTrustRegion	5.65 ± 0.38 μs	5.68 ± 0.47 μs	0.995 ± 0.11
multivariate/problems/saddle/2/Newton	4.26 ± 0.33 μs	4.32 ± 0.33 μs	0.986 ± 0.11
multivariate/problems/saddle/2/NewtonTrustRegion	9.2 ± 0.5 μs	9.19 ± 0.53 μs	1 ± 0.079
multivariate/problems/saddle/20/KrylovTrustRegion	12.1 ± 0.54 μs	12.3 ± 0.58 μs	0.978 ± 0.064
multivariate/problems/saddle/20/Newton	15.4 ± 0.67 μs	15.5 ± 0.65 μs	0.997 ± 0.06
multivariate/problems/saddle/20/NewtonTrustRegion	0.0837 ± 0.0031 ms	0.0855 ± 0.0026 ms	0.979 ± 0.047
multivariate/solvers/first_order/AdaMax	0.284 ± 0.0096 ms	0.285 ± 0.0097 ms	0.997 ± 0.048
multivariate/solvers/first_order/Adam	0.282 ± 0.01 ms	0.284 ± 0.0087 ms	0.994 ± 0.047
multivariate/solvers/first_order/BFGS	0.051 ± 0.0015 ms	0.0523 ± 0.0013 ms	0.975 ± 0.037
multivariate/solvers/first_order/ConjugateGradient	0.118 ± 0.005 ms	0.121 ± 0.0039 ms	0.979 ± 0.052
multivariate/solvers/first_order/GradientDescent	0.421 ± 0.012 ms	0.423 ± 0.016 ms	0.994 ± 0.046
multivariate/solvers/first_order/LBFGS	0.0615 ± 0.0011 ms	0.0622 ± 0.0017 ms	0.988 ± 0.031
multivariate/solvers/first_order/MomentumGradientDescent	0.807 ± 0.021 ms	0.792 ± 0.026 ms	1.02 ± 0.043
multivariate/solvers/first_order/NGMRES	0.254 ± 0.0085 ms	0.253 ± 0.0079 ms	1 ± 0.046
multivariate/solvers/second_order/KrylovTrustRegion	0.246 ± 0.01 ms	0.255 ± 0.0064 ms	0.967 ± 0.048
multivariate/solvers/second_order/Newton	0.0886 ± 0.0023 ms	0.0898 ± 0.0014 ms	0.987 ± 0.03
multivariate/solvers/second_order/NewtonTrustRegion	0.127 ± 0.0047 ms	0.13 ± 0.0037 ms	0.977 ± 0.045
time_to_load	0.227 ± 0.0061 s	0.213 ± 0.0042 s	1.07 ± 0.035

Memory benchmarks

	master	`1976c6b`...	master / `1976c6b`...
multivariate/problems/rosenbrock/100/KrylovTrustRegion	0.328 k allocs: 0.352 MB	0.328 k allocs: 0.352 MB	1
multivariate/problems/rosenbrock/100/Newton	0.369 k allocs: 0.339 MB	0.369 k allocs: 0.339 MB	1
multivariate/problems/rosenbrock/100/NewtonTrustRegion	0.416 k allocs: 6.43 MB	0.416 k allocs: 6.43 MB	1
multivariate/problems/rosenbrock/2/KrylovTrustRegion	0.332 k allocs: 21.4 kB	0.332 k allocs: 21.4 kB	1
multivariate/problems/rosenbrock/2/Newton	0.365 k allocs: 18.7 kB	0.365 k allocs: 18.7 kB	1
multivariate/problems/rosenbrock/2/NewtonTrustRegion	0.343 k allocs: 0.0348 MB	0.343 k allocs: 0.0348 MB	1
multivariate/problems/rosenbrock/20/KrylovTrustRegion	0.343 k allocs: 0.0618 MB	0.343 k allocs: 0.0618 MB	1
multivariate/problems/rosenbrock/20/Newton	0.365 k allocs: 0.0334 MB	0.365 k allocs: 0.0334 MB	1
multivariate/problems/rosenbrock/20/NewtonTrustRegion	0.33 k allocs: 0.396 MB	0.33 k allocs: 0.396 MB	1
multivariate/problems/saddle/100/KrylovTrustRegion	0.107 k allocs: 0.209 MB	0.107 k allocs: 0.209 MB	1
multivariate/problems/saddle/100/Newton	0.096 k allocs: 0.351 MB	0.096 k allocs: 0.351 MB	1
multivariate/problems/saddle/100/NewtonTrustRegion	0.255 k allocs: 3.51 MB	0.255 k allocs: 3.51 MB	1
multivariate/problems/saddle/2/KrylovTrustRegion	0.114 k allocs: 7.16 kB	0.114 k allocs: 7.16 kB	1
multivariate/problems/saddle/2/Newton	0.088 k allocs: 5.52 kB	0.088 k allocs: 5.52 kB	1
multivariate/problems/saddle/2/NewtonTrustRegion	0.129 k allocs: 13 kB	0.129 k allocs: 13 kB	1
multivariate/problems/saddle/20/KrylovTrustRegion	0.102 k allocs: 22.1 kB	0.102 k allocs: 22.1 kB	1
multivariate/problems/saddle/20/Newton	0.088 k allocs: 20.7 kB	0.088 k allocs: 20.7 kB	1
multivariate/problems/saddle/20/NewtonTrustRegion	0.139 k allocs: 0.155 MB	0.139 k allocs: 0.155 MB	1
multivariate/solvers/first_order/AdaMax	0.341 k allocs: 7.36 kB	0.341 k allocs: 7.36 kB	1
multivariate/solvers/first_order/Adam	0.341 k allocs: 7.36 kB	0.341 k allocs: 7.36 kB	1
multivariate/solvers/first_order/BFGS	0.157 k allocs: 8.67 kB	0.157 k allocs: 8.67 kB	1
multivariate/solvers/first_order/ConjugateGradient	0.37 k allocs: 19.4 kB	0.37 k allocs: 19.4 kB	1
multivariate/solvers/first_order/GradientDescent	1.22 k allocs: 0.065 MB	1.22 k allocs: 0.065 MB	1
multivariate/solvers/first_order/LBFGS	0.226 k allocs: 14 kB	0.226 k allocs: 14 kB	1
multivariate/solvers/first_order/MomentumGradientDescent	1.62 k allocs: 0.0713 MB	1.62 k allocs: 0.0713 MB	1
multivariate/solvers/first_order/NGMRES	1.68 k allocs: 0.142 MB	1.68 k allocs: 0.142 MB	1
multivariate/solvers/second_order/KrylovTrustRegion	0.229 k allocs: 13.5 kB	0.229 k allocs: 13.5 kB	1
multivariate/solvers/second_order/Newton	0.174 k allocs: 10.3 kB	0.174 k allocs: 10.3 kB	1
multivariate/solvers/second_order/NewtonTrustRegion	0.253 k allocs: 23 kB	0.253 k allocs: 23 kB	1
time_to_load	0.153 k allocs: 14.5 kB	0.153 k allocs: 14.5 kB	1

A plot of the benchmark results has been uploaded as an artifact at .

github-actions · 2026-10-17T18:29:25Z

Benchmark Results (Julia v1)

Time benchmarks

	master	`1976c6b`...	master / `1976c6b`...
multivariate/problems/rosenbrock/100/KrylovTrustRegion	0.164 ± 0.0098 ms	0.169 ± 0.0075 ms	0.971 ± 0.072
multivariate/problems/rosenbrock/100/Newton	1.39 ± 0.039 ms	1.32 ± 0.021 ms	1.05 ± 0.034
multivariate/problems/rosenbrock/100/NewtonTrustRegion	5.89 ± 0.44 ms	5.99 ± 0.46 ms	0.985 ± 0.11
multivariate/problems/rosenbrock/2/KrylovTrustRegion	21.4 ± 5.4 μs	22 ± 5.6 μs	0.972 ± 0.35
multivariate/problems/rosenbrock/2/Newton	26.6 ± 5.5 μs	27 ± 5.4 μs	0.987 ± 0.28
multivariate/problems/rosenbrock/2/NewtonTrustRegion	0.036 ± 0.0082 ms	0.0353 ± 0.0084 ms	1.02 ± 0.34
multivariate/problems/rosenbrock/20/KrylovTrustRegion	0.0384 ± 0.003 ms	0.0386 ± 0.0024 ms	0.997 ± 0.1
multivariate/problems/rosenbrock/20/Newton	0.0775 ± 0.0012 ms	0.0762 ± 0.0011 ms	1.02 ± 0.022
multivariate/problems/rosenbrock/20/NewtonTrustRegion	0.315 ± 0.015 ms	0.311 ± 0.014 ms	1.01 ± 0.066
multivariate/problems/saddle/100/KrylovTrustRegion	0.0553 ± 0.0061 ms	0.0585 ± 0.0046 ms	0.947 ± 0.13
multivariate/problems/saddle/100/Newton	0.25 ± 0.014 ms	0.245 ± 0.016 ms	1.02 ± 0.09
multivariate/problems/saddle/100/NewtonTrustRegion	3.1 ± 0.096 ms	3.16 ± 0.086 ms	0.981 ± 0.04
multivariate/problems/saddle/2/KrylovTrustRegion	8.33 ± 0.24 μs	8.61 ± 0.24 μs	0.967 ± 0.039
multivariate/problems/saddle/2/Newton	5.79 ± 0.32 μs	5.75 ± 0.31 μs	1.01 ± 0.078
multivariate/problems/saddle/2/NewtonTrustRegion	12.7 ± 1.1 μs	12.4 ± 1.1 μs	1.03 ± 0.13
multivariate/problems/saddle/20/KrylovTrustRegion	12.7 ± 5.2 μs	12.8 ± 5 μs	0.995 ± 0.56
multivariate/problems/saddle/20/Newton	16.4 ± 0.53 μs	16.1 ± 0.49 μs	1.02 ± 0.045
multivariate/problems/saddle/20/NewtonTrustRegion	0.107 ± 0.0073 ms	0.109 ± 0.005 ms	0.976 ± 0.08
multivariate/solvers/first_order/AdaMax	0.639 ± 0.012 ms	0.639 ± 0.0093 ms	1 ± 0.024
multivariate/solvers/first_order/Adam	0.637 ± 0.0095 ms	0.638 ± 0.0098 ms	0.998 ± 0.021
multivariate/solvers/first_order/BFGS	0.132 ± 0.002 ms	0.133 ± 0.002 ms	0.999 ± 0.022
multivariate/solvers/first_order/ConjugateGradient	0.22 ± 0.0066 ms	0.22 ± 0.0081 ms	1 ± 0.047
multivariate/solvers/first_order/GradientDescent	0.952 ± 0.006 ms	0.953 ± 0.0084 ms	0.999 ± 0.011
multivariate/solvers/first_order/LBFGS	0.149 ± 0.0028 ms	0.15 ± 0.0027 ms	0.997 ± 0.026
multivariate/solvers/first_order/MomentumGradientDescent	1.92 ± 0.017 ms	1.93 ± 0.016 ms	0.996 ± 0.012
multivariate/solvers/first_order/NGMRES	0.943 ± 0.0059 ms	0.946 ± 0.0076 ms	0.997 ± 0.01
multivariate/solvers/second_order/KrylovTrustRegion	0.331 ± 0.0097 ms	0.332 ± 0.0098 ms	0.996 ± 0.041
multivariate/solvers/second_order/Newton	0.222 ± 0.0065 ms	0.223 ± 0.0085 ms	0.998 ± 0.048
multivariate/solvers/second_order/NewtonTrustRegion	0.241 ± 0.0093 ms	0.243 ± 0.012 ms	0.994 ± 0.061
time_to_load	0.363 ± 0.0037 s	0.363 ± 0.0022 s	0.999 ± 0.012

Memory benchmarks

	master	`1976c6b`...	master / `1976c6b`...
multivariate/problems/rosenbrock/100/KrylovTrustRegion	0.561 k allocs: 0.36 MB	0.561 k allocs: 0.36 MB	1
multivariate/problems/rosenbrock/100/Newton	0.496 k allocs: 0.34 MB	0.496 k allocs: 0.34 MB	1
multivariate/problems/rosenbrock/100/NewtonTrustRegion	0.554 k allocs: 4.65 MB	0.554 k allocs: 4.65 MB	1
multivariate/problems/rosenbrock/2/KrylovTrustRegion	0.574 k allocs: 21.3 kB	0.574 k allocs: 21.3 kB	1
multivariate/problems/rosenbrock/2/Newton	0.492 k allocs: 18.4 kB	0.492 k allocs: 18.4 kB	1
multivariate/problems/rosenbrock/2/NewtonTrustRegion	0.458 k allocs: 0.0326 MB	0.458 k allocs: 0.0326 MB	1
multivariate/problems/rosenbrock/20/KrylovTrustRegion	0.595 k allocs: 0.0616 MB	0.595 k allocs: 0.0616 MB	1
multivariate/problems/rosenbrock/20/Newton	0.496 k allocs: 0.033 MB	0.496 k allocs: 0.033 MB	1
multivariate/problems/rosenbrock/20/NewtonTrustRegion	0.511 k allocs: 0.319 MB	0.511 k allocs: 0.319 MB	1
multivariate/problems/saddle/100/KrylovTrustRegion	0.173 k allocs: 0.211 MB	0.173 k allocs: 0.211 MB	1
multivariate/problems/saddle/100/Newton	0.141 k allocs: 0.352 MB	0.141 k allocs: 0.352 MB	1
multivariate/problems/saddle/100/NewtonTrustRegion	0.338 k allocs: 2.58 MB	0.338 k allocs: 2.58 MB	1
multivariate/problems/saddle/2/KrylovTrustRegion	0.183 k allocs: 7.09 kB	0.183 k allocs: 7.09 kB	1
multivariate/problems/saddle/2/Newton	0.129 k allocs: 5.75 kB	0.129 k allocs: 5.75 kB	1
multivariate/problems/saddle/2/NewtonTrustRegion	0.18 k allocs: 12.3 kB	0.18 k allocs: 12.3 kB	1
multivariate/problems/saddle/20/KrylovTrustRegion	0.17 k allocs: 21.9 kB	0.17 k allocs: 21.9 kB	1
multivariate/problems/saddle/20/Newton	0.133 k allocs: 20.8 kB	0.133 k allocs: 20.8 kB	1
multivariate/problems/saddle/20/NewtonTrustRegion	0.222 k allocs: 0.127 MB	0.222 k allocs: 0.127 MB	1
multivariate/solvers/first_order/AdaMax	0.356 k allocs: 7.27 kB	0.356 k allocs: 7.27 kB	1
multivariate/solvers/first_order/Adam	0.356 k allocs: 7.27 kB	0.356 k allocs: 7.27 kB	1
multivariate/solvers/first_order/BFGS	0.23 k allocs: 8.8 kB	0.23 k allocs: 8.8 kB	1
multivariate/solvers/first_order/ConjugateGradient	0.392 k allocs: 16 kB	0.392 k allocs: 16 kB	1
multivariate/solvers/first_order/GradientDescent	1.52 k allocs: 0.0611 MB	1.52 k allocs: 0.0611 MB	1
multivariate/solvers/first_order/LBFGS	0.325 k allocs: 14 kB	0.325 k allocs: 14 kB	1
multivariate/solvers/first_order/MomentumGradientDescent	1.91 k allocs: 0.0666 MB	1.91 k allocs: 0.0666 MB	1
multivariate/solvers/first_order/NGMRES	3.14 k allocs: 0.156 MB	3.14 k allocs: 0.156 MB	1
multivariate/solvers/second_order/KrylovTrustRegion	0.284 k allocs: 11.3 kB	0.284 k allocs: 11.3 kB	1
multivariate/solvers/second_order/Newton	0.251 k allocs: 10.2 kB	0.251 k allocs: 10.2 kB	1
multivariate/solvers/second_order/NewtonTrustRegion	0.302 k allocs: 19.1 kB	0.302 k allocs: 19.1 kB	1
time_to_load	0.2 k allocs: 11.7 kB	0.2 k allocs: 11.7 kB	1

A plot of the benchmark results has been uploaded as an artifact at .

pkofod · 2026-10-19T11:43:18Z

Thanks

codecov · 2026-10-19T11:53:08Z

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 87.53%. Comparing base (79cecbc) to head (1976c6b).
⚠️ Report is 8 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1294      +/-   ##
==========================================
+ Coverage   87.51%   87.53%   +0.01%     
==========================================
  Files          52       52              
  Lines        5032     5032              
==========================================
+ Hits         4404     4405       +1     
+ Misses        628      627       -1

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

inayatku · 2026-10-19T13:27:25Z

Thank you. The Julia 1 jobs stop before the tests run: on Julia 1.13.2 the test environment cannot install JET, because [compat] allows JET 0.9 to 0.11 and Julia 1.13 needs JET 0.12 (CompatHelper #1269 raises it). The lts and min jobs pass.

pkofod · 2026-10-19T14:52:30Z

shoudl work if you rebase

inayatku · 2026-10-21T16:52:11Z

Rebased onto master. Thank you.

pkofod · 2026-10-24T15:05:26Z

thanks!

ParticleSwarm: clamp c2 to 3/2 when it falls below 3/2

1976c6b

inayatku force-pushed the pso-c2-clamp branch from f057a36 to 1976c6b Compare October 21, 2026 16:51

pkofod merged commit 8e77e1e into JuliaNLSolvers:master Oct 24, 2026
14 checks passed

Navigation Menu

Repository navigation

ParticleSwarm: clamp c2 to 3/2 when it falls below 3/2 - #1294

ParticleSwarm: clamp c2 to 3/2 when it falls below 3/2#1294
pkofod merged 1 commit into
JuliaNLSolvers:masterfrom
inayatku:pso-c2-clamp

inayatku commented Oct 17, 2026

Uh oh!

github-actions Bot commented Oct 17, 2026 •

edited

Loading

Uh oh!

github-actions Bot commented Oct 17, 2026 •

edited

Loading

Uh oh!

pkofod commented Oct 19, 2026

Uh oh!

codecov Bot commented Oct 19, 2026 •

edited

Loading

Uh oh!

inayatku commented Oct 19, 2026

Uh oh!

pkofod commented Oct 19, 2026

Uh oh!

inayatku commented Oct 21, 2026

Uh oh!

pkofod commented Oct 24, 2026

Uh oh!

Uh oh!

Reviewers

Uh oh!

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

Conversation

inayatku commented Oct 17, 2026

Uh oh!

github-actions Bot commented Oct 17, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Benchmark Results (Julia vlts)

Uh oh!

github-actions Bot commented Oct 17, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Benchmark Results (Julia v1)

Uh oh!

pkofod commented Oct 19, 2026

Uh oh!

codecov Bot commented Oct 19, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Codecov Report

Uh oh!

inayatku commented Oct 19, 2026

Uh oh!

pkofod commented Oct 19, 2026

Uh oh!

inayatku commented Oct 21, 2026

Uh oh!

pkofod commented Oct 24, 2026

Uh oh!

Uh oh!

Reviewers

Uh oh!

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

github-actions Bot commented Oct 17, 2026 •

edited

Loading

github-actions Bot commented Oct 17, 2026 •

edited

Loading

codecov Bot commented Oct 19, 2026 •

edited

Loading