Rewrite

[cathaypacific8747]

We are rewriting the project to be more modular and typed. Since there will be significant breaking changes, commits will be added in the dev branch and merged into master once stabilised.

todo:

• Use uv (modern package manager)
• make web and era5 optional dependencies
• Use ruff (linting)
• Use mkdocs
• Use types whenever possible, check with mypy
• update testing
• do not hardcode cache paths #63
• replace staticmethods in Calculation, Unit, Nav to pure functions*
• Performance should not store Bada*
• split god objects*
• Use fastapi
  • update client: use simple REST calls instead of socketio (to automatically generate an OpenAPI spec and make
    debugging much easier)
  • remove code duplication
• drop requirement for conda
• migrate yarn to npm
• update docs

* will be addressed in the experimental module

non-goals:

• integrate with https://github.com/cathaypacific8747/fr24

some notes:

• makes heavy use of structure-of-arrays (Traffic, Autopilot)
• Environment responsible for many tasks: simulation, socket IO, file IO.
• Aircraft doesn't hold its own data, but acts as a pointer/slice to the arrays inside Traffic
  • dangling pointers when public Traffic.del_aircraft() is called
• environment spawned on socketio run_simulation signal

[cathaypacific8747]

ec51a70 introduces a new MIT-licensed experimental module that houses the rewrite.

The goal is to allow functions to accept not only NumPy arrays, but anything that conforms to the Array API, so we can do things like:

import jax
import jax.numpy as jnp

from airtrafficsim.experimental.geospatial import G_0
from airtrafficsim.experimental.performance.bada3 import atmosphere
from airtrafficsim.experimental.thermodynamics import R_SPECIFIC_DRY_AIR

"""
Test that the BADA3 atmosphere model can be differentiated with JAX,
and that it is under hydrostatic equilibrium.
"""
zs = jnp.linspace(0, 20000, 100)

dpdz = jax.vmap(
    jax.grad(lambda z: atmosphere(z, delta_temperature=0.0).pressure)
)(zs)
rho = atmosphere(zs, delta_temperature=0.0).density(R_SPECIFIC_DRY_AIR)

assert jnp.allclose(dpdz, -rho * G_0)

[cathaypacific8747]

f0256ec introduces support for the polars Lazy API:

import polars as pl

import numpy as np
from airtrafficsim.experimental.performance.bada3 import atmosphere


def calc_atmosphere(z: pl.Expr) -> tuple[pl.Expr, pl.Expr, pl.Expr]:
    res = atmosphere(z, delta_temperature=0.0)
    return (
        z,
        res.pressure.alias("pressure"),
        res.temperature.alias("temperature"),
    )


DATA = {
    "z": np.linspace(0, 20000, 50),
    # ... more data
}

lf = pl.DataFrame(DATA).lazy()
query = lf.select(calc_atmosphere(pl.col("z")))
print(query.explain())
print(query.collect())

Output

SELECT [col("z"), when(col("__POLARS_CSER_0xf23969390f922b2d")).then([(101325.0) * ([([(col("__POLARS_CSER_0x9c1f4281e110a6e6")) - (0.0)]) / (288.15)].pow([dyn float: 5.25588]))]).otherwise([(22632.06) * ([([(col("z")) - (11000.0)]) * (-0.000158)].exp())]).alias("pressure"), col("__POLARS_CSER_0x9c1f4281e110a6e6").alias("temperature")] FROM
   WITH_COLUMNS:
   [[(col("z")) <= (11000.0)].alias("__POLARS_CSER_0xf23969390f922b2d"), when([(col("z")) <= (11000.0)]).then([(288.15) + ([(col("z")) * (-0.0065)])]).otherwise(216.65).alias("__POLARS_CSER_0x9c1f4281e110a6e6")] 
    DF ["z"]; PROJECT 1/1 COLUMNS; SELECTION: None
shape: (50, 3)
┌──────────────┬──────────────┬─────────────┐
│ z            ┆ pressure     ┆ temperature │
│ ---          ┆ ---          ┆ ---         │
│ f64          ┆ f64          ┆ f64         │
╞══════════════╪══════════════╪═════════════╡
│ 0.0          ┆ 101325.0     ┆ 288.15      │
│ 408.163265   ┆ 96516.787991 ┆ 285.496939  │
│ 816.326531   ┆ 91895.021614 ┆ 282.843878  │
│ 1224.489796  ┆ 87454.118816 ┆ 280.190816  │
│ 1632.653061  ┆ 83188.614413 ┆ 277.537755  │
│ …            ┆ …            ┆ …           │
│ 18367.346939 ┆ 7082.460919  ┆ 216.65      │
│ 18775.510204 ┆ 6640.974885  ┆ 216.65      │
│ 19183.673469 ┆ 6227.008934  ┆ 216.65      │
│ 19591.836735 ┆ 5838.8476    ┆ 216.65      │
│ 20000.0      ┆ 5474.882348  ┆ 216.65      │
└──────────────┴──────────────┴─────────────┘

[cathaypacific8747]

Planned bug fixes:

• Invalid links to Climate Data Store #58
• Using a negative longitude in DemoEnv.py throws an error. #54
• Error while using piston/turboprop aircraft #59
• [Frontend] Error on running frontend #60