gpkit-models

This repository contains those GP-/SP-compatible models that we consider well documented and general enough to be useful to multiple projects.

• Simple models with in-depth explanations (good for learning GPkit)
  • SimPleAC: a basic aircraft model that captures the fundamental design tradeoffs
  • Economic Order Quantity: tradeoff between setup and holding costs
  • Cylindrical Beam Moment of Inertia: GP approximation of cylindrical beam MOI
  • Net Present Value: financial tradeoff between cash and equipment
  • Raymer Weights: rule-of-thumb weight relations for aircraft design
• GP models
  • Aircraft
    • Wing Structural and Aero Models
    • Empennage: TailBoom, HorizontalTail, and VerticalTail inherit from the Wing model
    • Mission: models that unify subsystems and flight profiles
    • Fuselage: elliptical and cylindrical fuselage models
    • IC Gas Engine Model
  • Bending Beam: discretized beam for distributed loads
• SP models
  • Aircraft
    • Tail Boom Flexibility
    • Wing Spanwise Effectiveness
  • Atmosphere
    • Tony Tao's fits as (efficient) signomial equalities. Valid until 10,000m of altitude.

Releasing

Versions are derived automatically from git tags (via hatch-vcs) — there is no __version__ to hand-edit and no version-bump PR to remember. gpkitmodels.__version__ reflects whatever tag is checked out:

• On a commit exactly at tag v0.2.0, with no local changes: 0.2.0.
• On any other commit: 0.2.1.devN+g<hash>, where N is commits since the last tag.
• With uncommitted local changes: the version always carries a dev/dirty suffix, even if HEAD is itself tagged — so a clean X.Y.Z version only ever comes from a committed, exactly-tagged commit.

To cut a release:

make release V=0.2.0

or directly:

gh release create v0.2.0 --generate-notes

Publishing the release triggers .github/workflows/publish.yml, which builds the package (version read straight from the new tag) and uploads it to PyPI.

Use plain vMAJOR.MINOR.PATCH tags. Bump PATCH for fixes, MINOR for backwards-compatible additions, MAJOR for breaking changes.