bug: run_simplex() returns empty dict {} on max iteration instead of raising an informative error

[jgohel9902]

Repository commit

791deb4

Python version (python --version)

Python 3.12.10

Dependencies version (pip freeze)

alembic==1.18.4
altair==5.5.0
annotated-doc==0.0.4
annotated-types==0.7.0
anyio==4.13.0
attrs==25.4.0
bcrypt==5.0.0
blinker==1.9.0
cachetools==5.5.2
certifi==2025.11.12
charset-normalizer==3.4.4
click==8.3.1
colorama==0.4.6
contourpy==1.3.3
cycler==0.12.1
distro==1.9.0
ecdsa==0.19.2
fastapi==0.135.3
fonttools==4.61.0
gitdb==4.0.12
GitPython==3.1.45
greenlet==3.4.0
groq==1.1.2
h11==0.16.0
httpcore==1.0.9
httpx==0.28.1
idna==3.11
importlib_metadata==7.2.1
iniconfig==2.3.0
Jinja2==3.1.6
joblib==1.4.2
jsonschema==4.25.1
jsonschema-specifications==2025.9.1
kiwisolver==1.4.9
Mako==1.3.10
markdown-it-py==4.0.0
MarkupSafe==3.0.3
matplotlib==3.10.7
mdurl==0.1.2
narwhals==2.12.0
nltk==3.9.2
numpy==1.26.4
packaging==23.2
pandas==2.2.3
pillow==10.4.0
pip==25.3
pluggy==1.6.0
protobuf==4.25.8
psycopg2-binary==2.9.11
pyarrow==21.0.0
pyasn1==0.6.3
pydantic==2.13.0
pydantic_core==2.46.0
pydeck==0.9.1
Pygments==2.19.2
pyodbc==5.3.0
pyparsing==3.2.5
pytest==9.0.3
pytest-asyncio==1.3.0
python-dateutil==2.9.0.post0
python-jose==3.5.0
python-multipart==0.0.26
pytz==2025.2
referencing==0.37.0
regex==2025.11.3
requests==2.32.5
rich==13.9.4
rpds-py==0.29.0
rsa==4.9.1
scikit-learn==1.5.2
scipy==1.16.3
six==1.17.0
smmap==5.0.2
sniffio==1.3.1
SQLAlchemy==2.0.49
starlette==1.0.0
streamlit==1.31.0
tenacity==8.5.0
textblob==0.19.0
threadpoolctl==3.6.0
toml==0.10.2
tornado==6.5.2
tqdm==4.67.1
typing-inspection==0.4.2
typing_extensions==4.15.0
tzdata==2025.2
tzlocal==5.3.1
urllib3==2.5.0
uvicorn==0.44.0
validators==0.35.0
watchdog==6.0.0
zipp==3.23.0

Expected behavior

run_simplex() should raise a descriptive ValueError when the maximum iteration limit is reached, so the caller can distinguish between a cycling problem and an actual empty solution.

Example:
raise ValueError(
f"Simplex did not converge within {Tableau.maxiter} iterations. "
"The problem may be cycling or unbounded."
)

Actual behavior

run_simplex() silently returns an empty dict {} when maxiter is
exhausted, with no indication of why it failed or that it failed
at all.

[MeriemBchini]

#14586

[unn-Known1]

I have submitted a fix for this issue in PR #14590.

The run_simplex() method now raises a descriptive ValueError when the maximum iteration limit is reached, instead of silently returning an empty dict.

Changes made:

• Modified run_simplex() to raise ValueError with message: "Simplex did not converge within {maxiter} iterations. The problem may be cycling or unbounded."

This allows callers to distinguish between a converging solution and a cycling/unbounded problem.