clj-physics

An idiomatic Clojure toolkit for multi-domain physics modeling. It brings together coordinate frames, environmental models, vehicle dynamics, constraints, integrators/observers, CFD helpers, electromagnetics, and spatial utilities under a single physics.* namespace tree.

Features

• Core math: vectors, quaternions, rotation/transform helpers (physics.core).
• Spatial: poses, frames, geometry/topology utilities (physics.spatial.*).
• Frames: WGS84, geodetic↔ECEF/ENU transforms, Earth constants (physics.frames).
• Environment: ISA atmosphere, seawater properties, gravity (physics.environment).
• Dynamics: airframe, ground, maritime, subsurface, orbital dynamics; force/moment models (physics.dynamics).
• Constraints: envelopes for speed/Mach/G/bank/depth (physics.constraints).
• Integrators: RK4 and RKF45 adaptive integrators (physics.integrators).
• Observer: trajectory projection and synthetic telemetry generation (physics.observer).
• Models: representative platforms (fixed-wing, UGV, USV, submarine, Earth) (physics.models.common).
• CFD: geometry/environment schemas, surrogate+corrector pipeline, plume/maritime/debris helpers (physics.cfd.*).
• Electromagnetics: robust complex math, materials, fields, propagation, constraints (physics.electromagnetics.*).

Install

Pull from Clojars:

;; deps.edn
net.clojars.helsingin/physics {:mvn/version "<latest from https://clojars.org/net.clojars.helsingin/physics>"}

Quick Start

(require '[physics.electromagnetics.fields :as f]
         '[physics.electromagnetics.materials :as m]
         '[physics.electromagnetics.propagation :as p]
         '[physics.frames :as frames]
         '[physics.environment :as env]
         '[physics.dynamics :as dyn])

;; Build a field and propagate it
(def field (f/->field {:type :electric :frequency-hz 2.4e9 :amplitude 1.0 :orientation [0 0 1]}))
(def air (m/->material {:name "air" :type :dielectric :permittivity-relative 1.0006 :permeability-relative 1.0 :conductivity 0.0}))
(p/propagate-plane-wave field air 100.0)

;; Frame transforms
(def origin {:position [37.62 -122.38 0.0]})
(frames/geodetic->ecef {:lat 37.62 :lon -122.38 :alt 0.0})

;; Dynamics: compute derivatives for a fixed-wing state
(def model (physics.models.common/fixed-wing))
(def state {:position [0 0 1000]
            :velocity [60 0 0]
            :orientation (physics.core/euler->quaternion {:roll 0 :pitch 0 :yaw 0})
            :angular-rate [0 0 0]})
(dyn/rigid-body-derivatives model state (env/isa-profile 1000) {:throttle 0.5})

Tests

clojure -M:test

Tests cover core math, frames, environment, dynamics, constraints, integrators, observer, CFD, electromagnetics, and spatial utilities. A default tests.edn is included for Kaocha with a pinned seed.

Build and release

• Build the jar: clojure -T:build jar
• Deploy to Clojars: make deploy (reads credentials from ~/.m2/settings.xml server clojars, or falls back to CLOJARS_USERNAME/CLOJARS_PASSWORD if exported)

Logging

A simple logback config lives in dev/logback.xml. SLF4J binding is pulled in test/dev via the :test alias; production users can supply their own binding or exclude it.

License

Licensed under GPL-3.0-only. See LICENSE for details.