stan-dev/math
Jul 2025 – Feb 2026
4 Months active
Languages Used
C++
Technical Skills
C++ DevelopmentProbability DistributionsStatistical ModelingUnit TestingMathematical LibrariesSoftware Testing
Ling Zhi
PROFILE
Ling Zhi
Over four months, contributed to the stan-dev/math repository by developing and refining statistical distribution functions in C++. Delivered core implementations for the Yule-Simon distribution, including log PMF, LCCDF, LCDF, and CDF, with a focus on robust input handling, numerical accuracy, and comprehensive unit testing. Enhanced derivative calculations for autodiff workflows, improving both correctness and performance in probabilistic modeling. Applied statistical modeling and software testing skills to expand test coverage, address edge cases, and ensure code maintainability. The work emphasized reliability and future-proofing for production modeling, reinforcing the repository’s mathematical library with well-tested, production-ready statistical functionality.
Overall Statistics
Feature vs Bugs
75%Features
Repository Contributions
8Total
Bugs
1
Commits
8
Features
3
Lines of code
651
Activity Months4
Your Network
18 peopleWork History
February 2026
3 Commits • 1 Features
Feb 1, 2026February 2026: Delivered Yule-Simon CDF support in stan-dev/math, including LCDF and CDF implementations and edge-case tests for the lower tail. Added three commits to implement and test the distribution, reinforcing numerical robustness. No major bug fixes this month; core achievements center on feature delivery and test coverage, enabling more accurate probabilistic modeling and reducing risk in downstream applications. Technologies demonstrated include C++ development, numerical methods, unit testing, and test-driven development.
3 Commits • 1 Features
Feb 1, 2026February 2026: Delivered Yule-Simon CDF support in stan-dev/math, including LCDF and CDF implementations and edge-case tests for the lower tail. Added three commits to implement and test the distribution, reinforcing numerical robustness. No major bug fixes this month; core achievements center on feature delivery and test coverage, enabling more accurate probabilistic modeling and reducing risk in downstream applications. Technologies demonstrated include C++ development, numerical methods, unit testing, and test-driven development.
February 2026
October 2025
1 Commits
Oct 1, 2025October 2025 monthly summary for stan-dev/math focusing on correctness and performance in autodiff paths. Delivered update improves derivative gating for Yule-Simon LCCDF to compute partial derivatives only when alpha requires differentiation, reducing unnecessary work and ensuring correct derivatives for autodiff usage. Commit 94dda8f755926433e6d93834919df69c5543d4d6 updated stan/math/prim/prob/yule_simon_lccdf.hpp. This work enhances reliability of probabilistic computations involving LCCDF and supports heavier autodiff workloads.
October 2025
1 Commits
Oct 1, 2025October 2025 monthly summary for stan-dev/math focusing on correctness and performance in autodiff paths. Delivered update improves derivative gating for Yule-Simon LCCDF to compute partial derivatives only when alpha requires differentiation, reducing unnecessary work and ensuring correct derivatives for autodiff usage. Commit 94dda8f755926433e6d93834919df69c5543d4d6 updated stan/math/prim/prob/yule_simon_lccdf.hpp. This work enhances reliability of probabilistic computations involving LCCDF and supports heavier autodiff workloads.
September 2025
2 Commits • 1 Features
Sep 1, 2025Month: 2025-09 — Focused on delivering technical capabilities that drive accurate probabilistic modeling and code quality improvements in Stan Math. The principal delivery this month was a robust Yule-Simon LCCDF implementation with derivative refinements, supported by expanded test coverage and code updates to improve readability and maintainability. No major user-facing bug fixes were required; the work centered on correctness, testability, and future-proofing for distribution modeling in production workflows.
2 Commits • 1 Features
Sep 1, 2025Month: 2025-09 — Focused on delivering technical capabilities that drive accurate probabilistic modeling and code quality improvements in Stan Math. The principal delivery this month was a robust Yule-Simon LCCDF implementation with derivative refinements, supported by expanded test coverage and code updates to improve readability and maintainability. No major user-facing bug fixes were required; the work centered on correctness, testability, and future-proofing for distribution modeling in production workflows.
September 2025
July 2025
2 Commits • 1 Features
Jul 1, 2025Concise monthly summary focusing on delivering robust statistical functionality in stan-dev/math for 2025-07. The effort centered on implementing the Yule-Simon distribution log PMF (lpmf) with comprehensive input handling, unit tests, and accuracy improvements, along with clear traceability to commits.
July 2025
2 Commits • 1 Features
Jul 1, 2025Concise monthly summary focusing on delivering robust statistical functionality in stan-dev/math for 2025-07. The effort centered on implementing the Yule-Simon distribution log PMF (lpmf) with comprehensive input handling, unit tests, and accuracy improvements, along with clear traceability to commits.
Activity
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Quality Metrics
Correctness95.0%
Maintainability97.6%
Architecture95.0%
Performance92.6%
AI Usage20.0%
Skills & Technologies
Programming Languages
C++
Technical Skills
C++C++ DevelopmentC++ developmentMathematical LibrariesProbability DistributionsSoftware TestingStatistical ModelingUnit Testingmathematical modelingstatistical analysisstatistical programmingunit testing
Repositories Contributed To
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