fix(copy): keep frozen constraints frozen in Model.copy by FabianHofmann · Pull Request #982 · PyPSA/linopy

FabianHofmann · 2026-09-25T05:39:52Z

Closes #981.

Note

The following content was generated by AI.

Changes proposed in this Pull Request

Model.copy() (and copy.copy/copy.deepcopy) rebuilt every constraint as Constraint(con.mutable().data, ...), so a frozen CSRConstraint came back dense while the copy kept freeze_constraints=True.

linopy/io.py: a frozen constraint is copied through CSRConstraint._replace, rebound to the new model. deep=True copies its CSR and per-row arrays, deep=False shares them; without include_solution the dual is dropped, as for dense constraints. Dense constraints are copied as before.
The CSR-backed objective was kept sparse but shared its matrix and constant even with deep=True; it is now deep-copied too.
linopy/csr.py: Grid stores its auxiliary coordinate arrays read-only (copying writable input first, so the user's array is not flagged). The grid is therefore immutable and can be shared by copies. Before, writing to con.coords["aux"].values on any frozen constraint changed the grid in place, and after a deep copy also the original.

Tests

test_copy_frozen_matrices[deep]: solver-free, runs under legacy and v1. Frozen model with mask, row scaling, aux coord and an indicator constraint; the copy keeps CSRConstraint, A/b/sense/clabels and the indicator matrices equal the original's, buffers are shared exactly when deep=False, aux coords are read-only.
test_copy_keeps_frozen_constraints[deep, include_solution] (v1, HiGHS): softened frozen model with sparse objective; objective stays sparse, slack resolves in the copy, duals only with include_solution=True.
test_softening_frozen_copy_leaves_original[deep]: softening the copy leaves the original constraint and objective unchanged.
The copy tests fail on master and pass with the fix. A review pass also compared matrices and LP files of original and copy for softened, masked, scaled, aux-coord, mixed dense/frozen and indicator models under both semantics, checked duals and label counters after copy, and in-place operations on shallow copies.

Local results

Full suite without xpress (no license) and test/remote (oetc extras missing): 7113 passed, 0 failed.
ruff check, ruff format: clean. mypy: only the local-stub error at test/test_solvers.py:225, not present in CI.

Checklist

AI-generated content is marked (see AGENTS.md).
Code changes are sufficiently documented; i.e. new functions contain docstrings and further explanations may be given in doc.
Unit tests for new features were added (if applicable).
A note for the release notes doc/release_notes.rst of the upcoming release is included.
I consent to the release of this PR's code under the MIT license.

codspeed · 2026-09-25T05:43:24Z

Merging this PR will regress 1 benchmark

⚠️

Different runtime environments detected

Some benchmarks with significant performance changes were compared across different runtime environments,
which may affect the accuracy of the results.

Open the report in CodSpeed to investigate

⚡ 16 improved benchmarks
❌ 1 regressed benchmark
✅ 164 untouched benchmarks
⏩ 181 skipped benchmarks¹

Warning

Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Benchmark	`BASE`	`HEAD`	Efficiency
❌	`test_to_lp[expression_arithmetic-n=250]`	42.8 MB	50 MB	-14.38%
⚡	`test_to_lp[qp-n=1000]`	2,646.5 KB	795.3 KB	×3.3
⚡	`test_to_lp[masked-n=100]`	2,793.7 KB	892.8 KB	×3.1
⚡	`test_to_lp[milp-n=50]`	2,760 KB	885.4 KB	×3.1
⚡	`test_to_lp[sos-n=1000]`	3 MB	1.4 MB	×2.2
⚡	`test_to_lp[expression_arithmetic-n=10]`	1,339.1 KB	691.1 KB	+93.76%
⚡	`test_to_lp[sparse_network-n=10]`	1,337.7 KB	695.6 KB	+92.3%
⚡	`test_to_lp[storage-n=10]`	2.9 MB	1.6 MB	+78.9%
⚡	`test_to_lp[piecewise-n=1000]`	3 MB	1.9 MB	+60.75%
⚡	`test_to_lp[rolling-severity=0]`	3.1 MB	2 MB	+57.33%
⚡	`test_to_lp[cumsum-severity=50]`	62.3 MB	43.1 MB	+44.74%
⚡	`test_to_lp[knapsack-n=10000]`	3 MB	2.1 MB	+40.41%
⚡	`test_to_lp[cumsum-severity=100]`	208.9 MB	160.9 MB	+29.83%
⚡	`test_to_lp[rolling-severity=50]`	429.9 MB	333.9 MB	+28.76%
⚡	`test_to_lp[rolling-severity=100]`	274.6 MB	227 MB	+20.97%
⚡	`test_to_lp[kvl_cycles-severity=0]`	280.9 MB	232.9 MB	+20.61%
⚡	`test_to_lp[kvl_cycles-severity=50]`	141.6 MB	117.6 MB	+20.41%

Tip

Investigate this regression by commenting @codspeedbot fix this regression on this PR, or directly use the CodSpeed MCP with your agent.

_{Comparing fix/copy-frozen-constraints (2b8f02f) with master (14f601e)²}

181 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩
No successful run was found on master (bee7d1f) during the generation of this report, so 14f601e was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩

github-actions · 2026-09-25T05:43:27Z

Build cost — v1 vs legacy

v1 build peak & time relative to legacy, on this commit — not a comparison against master (that is CodSpeed).

peak — v1 / legacy	time — v1 / legacy

Full table (time + peak, mean)

benchmarks/drivers/test_build.py::test_build[basic-n=10]
                  time (s)         peak (KiB) 
 name                 mean   │           mean 
──────────────────────────────────────────────
 (legacy)   0.09354 (1.13)   │   15.03 (1.00) 
 (v1)        0.08298 (1.0)   │    15.00 (1.0) 

benchmarks/drivers/test_build.py::test_build[basic-n=250]
                  time (s)         peak (MiB) 
 name                 mean   │           mean 
──────────────────────────────────────────────
 (legacy)   0.09539 (1.06)   │   12.04 (1.00) 
 (v1)        0.09019 (1.0)   │    12.04 (1.0) 

benchmarks/drivers/test_build.py::test_build[cumsum-severity=0]
                 time (s)        peak (KiB) 
 name                mean   │          mean 
────────────────────────────────────────────
 (legacy)   0.0387 (1.07)   │   15.20 (1.0) 
 (v1)       0.03616 (1.0)   │   15.20 (1.0) 

benchmarks/drivers/test_build.py::test_build[cumsum-severity=100]
                  time (s)        peak (MiB) 
 name                 mean   │          mean 
─────────────────────────────────────────────
 (legacy)   0.05547 (1.04)   │   44.93 (1.0) 
 (v1)        0.05333 (1.0)   │   44.93 (1.0) 

benchmarks/drivers/test_build.py::test_build[cumsum-severity=50]
                  time (s)        peak (MiB) 
 name                 mean   │          mean 
─────────────────────────────────────────────
 (legacy)   0.04211 (1.06)   │   11.51 (1.0) 
 (v1)        0.03974 (1.0)   │   11.51 (1.0) 

benchmarks/drivers/test_build.py::test_build[expression_arithmetic-n=10]
                  time (s)         peak (KiB) 
 name                 mean   │           mean 
──────────────────────────────────────────────
 (legacy)   0.09898 (1.02)   │   24.34 (1.06) 
 (v1)         0.0966 (1.0)   │    23.04 (1.0) 

benchmarks/drivers/test_build.py::test_build[expression_arithmetic-n=250]
                 time (s)         peak (MiB) 
 name                mean   │           mean 
─────────────────────────────────────────────
 (legacy)   0.1094 (1.04)   │   16.12 (1.00) 
 (v1)        0.1052 (1.0)   │    16.12 (1.0) 

benchmarks/drivers/test_build.py::test_build[knapsack-n=10000]
                  time (s)          peak (KiB) 
 name                 mean   │            mean 
───────────────────────────────────────────────
 (legacy)   0.02387 (1.04)   │   752.18 (1.10) 
 (v1)        0.02298 (1.0)   │    685.15 (1.0) 

benchmarks/drivers/test_build.py::test_build[knapsack-n=100]
                  time (s)        peak (KiB) 
 name                 mean   │          mean 
─────────────────────────────────────────────
 (legacy)   0.02335 (1.04)   │   3.12 (1.33) 
 (v1)        0.02248 (1.0)   │    2.34 (1.0) 

benchmarks/drivers/test_build.py::test_build[kvl_cycles-severity=0]
                  time (s)          peak (MiB) 
 name                 mean   │            mean 
───────────────────────────────────────────────
 (legacy)   0.06501 (1.21)   │   126.16 (1.44) 
 (v1)        0.05365 (1.0)   │     87.71 (1.0) 

benchmarks/drivers/test_build.py::test_build[kvl_cycles-severity=100]
                  time (s)          peak (MiB) 
 name                 mean   │            mean 
───────────────────────────────────────────────
 (legacy)   0.06413 (1.22)   │   126.16 (1.44) 
 (v1)        0.05253 (1.0)   │     87.71 (1.0) 

benchmarks/drivers/test_build.py::test_build[kvl_cycles-severity=50]
                  time (s)          peak (MiB) 
 name                 mean   │            mean 
───────────────────────────────────────────────
 (legacy)   0.06447 (1.22)   │   126.16 (1.44) 
 (v1)        0.05299 (1.0)   │     87.71 (1.0) 

benchmarks/drivers/test_build.py::test_build[masked-n=100]
                  time (s)          peak (KiB) 
 name                 mean   │            mean 
───────────────────────────────────────────────
 (legacy)   0.05556 (1.01)   │    715.12 (1.0) 
 (v1)        0.05509 (1.0)   │   787.73 (1.10) 

benchmarks/drivers/test_build.py::test_build[masked-n=10]
                  time (s)        peak (KiB) 
 name                 mean   │          mean 
─────────────────────────────────────────────
 (legacy)   0.05383 (1.09)   │   4.54 (1.27) 
 (v1)         0.0496 (1.0)   │    3.57 (1.0) 

benchmarks/drivers/test_build.py::test_build[merge_balance-severity=0]
                 time (s)          peak (KiB) 
 name                mean   │            mean 
──────────────────────────────────────────────
 (legacy)   0.3733 (1.02)   │   704.12 (1.09) 
 (v1)        0.3674 (1.0)   │    643.85 (1.0) 

benchmarks/drivers/test_build.py::test_build[merge_balance-severity=100]
                 time (s)        peak (MiB) 
 name                mean   │          mean 
────────────────────────────────────────────
 (legacy)   0.3935 (1.02)   │   18.34 (1.0) 
 (v1)        0.3851 (1.0)   │   18.34 (1.0) 

benchmarks/drivers/test_build.py::test_build[merge_balance-severity=50]
                 time (s)       peak (MiB) 
 name                mean   │         mean 
───────────────────────────────────────────
 (legacy)   0.3907 (1.03)   │   9.54 (1.0) 
 (v1)        0.3805 (1.0)   │   9.54 (1.0) 

benchmarks/drivers/test_build.py::test_build[milp-n=10]
                  time (s)        peak (KiB) 
 name                 mean   │          mean 
─────────────────────────────────────────────
 (legacy)   0.07613 (1.07)   │   3.77 (1.12) 
 (v1)        0.07143 (1.0)   │    3.37 (1.0) 

benchmarks/drivers/test_build.py::test_build[milp-n=50]
                  time (s)          peak (KiB) 
 name                 mean   │            mean 
───────────────────────────────────────────────
 (legacy)   0.07671 (1.07)   │   216.59 (1.10) 
 (v1)         0.0715 (1.0)   │    196.23 (1.0) 

benchmarks/drivers/test_build.py::test_build[nodal_balance-severity=0]
                  time (s)         peak (KiB) 
 name                 mean   │           mean 
──────────────────────────────────────────────
 (legacy)   0.03836 (1.08)   │   938.49 (1.0) 
 (v1)        0.03568 (1.0)   │   938.49 (1.0) 

benchmarks/drivers/test_build.py::test_build[nodal_balance-severity=100]
                  time (s)       peak (MiB) 
 name                 mean   │         mean 
────────────────────────────────────────────
 (legacy)   0.03992 (1.09)   │   9.66 (1.0) 
 (v1)        0.03649 (1.0)   │   9.66 (1.0) 

benchmarks/drivers/test_build.py::test_build[nodal_balance-severity=50]
                  time (s)       peak (MiB) 
 name                 mean   │         mean 
────────────────────────────────────────────
 (legacy)   0.03927 (1.09)   │   5.32 (1.0) 
 (v1)        0.03606 (1.0)   │   5.32 (1.0) 

benchmarks/drivers/test_build.py::test_build[nodal_balance_sparse-severity=0]
                  time (s)       peak (MiB) 
 name                 mean   │         mean 
────────────────────────────────────────────
 (legacy)   0.02139 (1.01)   │   1.28 (1.0) 
 (v1)        0.02109 (1.0)   │   1.28 (1.0) 

benchmarks/drivers/test_build.py::test_build[nodal_balance_sparse-severity=100]
                  time (s)       peak (MiB) 
 name                 mean   │         mean 
────────────────────────────────────────────
 (legacy)    0.02128 (1.0)   │   1.28 (1.0) 
 (v1)       0.02145 (1.01)   │   1.28 (1.0) 

benchmarks/drivers/test_build.py::test_build[nodal_balance_sparse-severity=50]
                 time (s)       peak (MiB) 
 name                mean   │         mean 
───────────────────────────────────────────
 (legacy)   0.0214 (1.00)   │   1.28 (1.0) 
 (v1)       0.02136 (1.0)   │   1.28 (1.0) 

benchmarks/drivers/test_build.py::test_build[piecewise-n=1000]
                time (s)          peak (KiB) 
 name               mean   │            mean 
─────────────────────────────────────────────
 (legacy)   0.189 (1.03)   │   946.85 (1.06) 
 (v1)        0.183 (1.0)   │    891.54 (1.0) 

benchmarks/drivers/test_build.py::test_build[piecewise-n=10]
                 time (s)         peak (KiB) 
 name                mean   │           mean 
─────────────────────────────────────────────
 (legacy)   0.1851 (1.03)   │   12.01 (1.00) 
 (v1)        0.1804 (1.0)   │    11.99 (1.0) 

benchmarks/drivers/test_build.py::test_build[qp-n=1000]
                  time (s)          peak (KiB) 
 name                 mean   │            mean 
───────────────────────────────────────────────
 (legacy)   0.04911 (1.08)   │   147.70 (1.06) 
 (v1)        0.04562 (1.0)   │    139.87 (1.0) 

benchmarks/drivers/test_build.py::test_build[qp-n=10]
                 time (s)        peak (KiB) 
 name                mean   │          mean 
────────────────────────────────────────────
 (legacy)   0.0478 (1.06)   │   2.60 (1.09) 
 (v1)       0.04517 (1.0)   │    2.38 (1.0) 

benchmarks/drivers/test_build.py::test_build[rolling-severity=0]
                  time (s)          peak (KiB) 
 name                 mean   │            mean 
───────────────────────────────────────────────
 (legacy)   0.03942 (1.08)   │   696.75 (1.03) 
 (v1)        0.03666 (1.0)   │    673.70 (1.0) 

benchmarks/drivers/test_build.py::test_build[rolling-severity=100]
                  time (s)         peak (MiB) 
 name                 mean   │           mean 
──────────────────────────────────────────────
 (legacy)   0.08762 (1.04)   │   137.97 (1.0) 
 (v1)        0.08406 (1.0)   │   137.97 (1.0) 

benchmarks/drivers/test_build.py::test_build[rolling-severity=50]
                  time (s)        peak (MiB) 
 name                 mean   │          mean 
─────────────────────────────────────────────
 (legacy)   0.06094 (1.07)   │   69.22 (1.0) 
 (v1)        0.05706 (1.0)   │   69.22 (1.0) 

benchmarks/drivers/test_build.py::test_build[sos-n=1000]
                  time (s)          peak (KiB) 
 name                 mean   │            mean 
───────────────────────────────────────────────
 (legacy)   0.04588 (1.10)   │   402.33 (1.00) 
 (v1)        0.04172 (1.0)   │    402.30 (1.0) 

benchmarks/drivers/test_build.py::test_build[sos-n=10]
                  time (s)        peak (KiB) 
 name                 mean   │          mean 
─────────────────────────────────────────────
 (legacy)   0.04563 (1.10)   │   3.19 (1.19) 
 (v1)        0.04144 (1.0)   │    2.69 (1.0) 

benchmarks/drivers/test_build.py::test_build[sparse_network-n=10]
                  time (s)         peak (KiB) 
 name                 mean   │           mean 
──────────────────────────────────────────────
 (legacy)   0.04966 (1.06)   │   29.00 (1.54) 
 (v1)        0.04699 (1.0)   │    18.84 (1.0) 

benchmarks/drivers/test_build.py::test_build[sparse_network-n=250]
                  time (s)         peak (MiB) 
 name                 mean   │           mean 
──────────────────────────────────────────────
 (legacy)   0.05996 (1.10)   │   37.95 (1.43) 
 (v1)        0.05441 (1.0)   │    26.51 (1.0) 

benchmarks/drivers/test_build.py::test_build[storage-n=10]
                  time (s)          peak (KiB) 
 name                 mean   │            mean 
───────────────────────────────────────────────
 (legacy)    0.09378 (1.0)   │    410.93 (1.0) 
 (v1)       0.09832 (1.05)   │   427.84 (1.04) 

benchmarks/drivers/test_build.py::test_build[storage-n=250]
                 time (s)         peak (MiB) 
 name                mean   │           mean 
─────────────────────────────────────────────
 (legacy)    0.1003 (1.0)   │     9.94 (1.0) 
 (v1)       0.1053 (1.05)   │   10.22 (1.03)

📊 Interactive plots + CSV: download the semantics-report-v1-vs-legacy artifact from this run.

_{Report-only · not a gate · refreshed on every push · obsolete once legacy is dropped.}

FabianHofmann added 3 commits September 25, 2026 07:26

fix(copy): keep frozen constraints frozen in Model.copy (#981)

c5e15aa

fix(copy): read-only grid aux coords, semantics-independent copy test

5188f9b

docs: restore release notes dropped in copy fix

d8db610

FabianHofmann added bug Something isn't working sparse Sparse / CSR-backed expressions and constraints labels Sep 25, 2026

FabianHofmann added 2 commits September 25, 2026 08:02

Merge branch 'master' into fix/copy-frozen-constraints

6f978f5

Merge branch 'master' into fix/copy-frozen-constraints

2b8f02f

FabianHofmann merged commit 0a33c37 into master Sep 25, 2026
21 of 22 checks passed

FabianHofmann deleted the fix/copy-frozen-constraints branch September 25, 2026 06:18

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fix(copy): keep frozen constraints frozen in Model.copy - #982

fix(copy): keep frozen constraints frozen in Model.copy#982
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FabianHofmann commented Sep 25, 2026

Changes proposed in this Pull Request

Tests

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Merging this PR will regress 1 benchmark

Performance Changes

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Build cost — v1 vs legacy

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