Files
giant/tests/test_particles.py
T
lars 68fb99bed8 Condition on material/particle physical properties instead of learned embeddings
Adds model.conditioning = "physical" | "embedding": physical mode routes
particle mass/charge and material Z_eff/A_eff/density/X0/lambda_int through
small MLPs to replace the learned PDG/material embedding tables, so the
surrogate generalizes to PDG codes/materials outside the training vocab
instead of memorizing it. "embedding" stays available as the comparison
baseline (old checkpoints without the key default to it).

Stage 2 now regresses a secondary's mass/charge directly against a fixed
physics-derived target instead of a learned/snapped embedding, and uses no
snapping at inference — the model's raw predicted (mass, charge) is the
secondary's physical identity, including for its own further rollout steps.
A separate reporting-only nearest-known-PDG lookup (never fed back into the
model) populates output pdg columns / the embedding-mode rollout fallback.

giant/materials.py's table is populated with Geant4's own built-in NIST
constants (Z_eff, A_eff, density, X0, lambda_int), extracted directly from
the Geant4 11.4.1 build vendored in minicalosim via G4NistManager rather
than hand-typed literature values. G4_LYSO is left unfilled: confirmed (both
by runtime lookup and by searching minicalosim's history) that it's never
actually a constructed Geant4 material there, only documentation/UI color-map
text.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
2026-07-17 15:12:54 +02:00

119 lines
3.9 KiB
Python

import numpy as np
import pytest
from giant.particles import (
nearest_known_pdg,
particle_mass_charge,
particle_phys_array,
)
def test_photon_massless_neutral():
mass, charge = particle_mass_charge(22)
assert mass == pytest.approx(0.0)
assert charge == pytest.approx(0.0)
def test_electron_mass_charge():
mass, charge = particle_mass_charge(11)
assert mass == pytest.approx(0.51099895069, rel=1e-6)
assert charge == pytest.approx(-1.0)
def test_positron_is_charge_conjugate_of_electron():
mass_e, charge_e = particle_mass_charge(11)
mass_p, charge_p = particle_mass_charge(-11)
assert mass_p == pytest.approx(mass_e)
assert charge_p == pytest.approx(-charge_e)
def test_proton_mass_charge():
mass, charge = particle_mass_charge(2212)
assert mass == pytest.approx(938.27208943, rel=1e-6)
assert charge == pytest.approx(1.0)
def test_neutrino_unmeasured_mass_treated_as_zero():
"""PDG tables store an unmeasured neutrino mass as None -- must not
propagate a None/NaN into a physical conditioning feature."""
mass, charge = particle_mass_charge(12)
assert mass == pytest.approx(0.0)
assert charge == pytest.approx(0.0)
def test_ground_state_nucleus_resolved_via_particle_package():
"""He-4 (Z=2, A=4) is a common nuclide in `particle`'s ground-state table."""
mass, charge = particle_mass_charge(1000020040)
assert charge == pytest.approx(2.0)
assert mass == pytest.approx(
4 * 931.494, rel=0.05
) # near A*amu, binding-energy-corrected
def test_nuclear_isomer_falls_back_to_z_a_decode():
"""An excited/isomer nuclear code (nonzero trailing digit) is absent from
`particle`'s ground-state-only nuclide table -- confirmed necessary for
~32% of the nuclear codes in the multi-material dataset. Fe-56 isomer:
Z=26, A=56, isomer level 1 -> pdgid 1000260561."""
pdg = 1000260561
mass, charge = particle_mass_charge(pdg)
assert charge == pytest.approx(26.0)
assert mass == pytest.approx(56 * 931.494, rel=1e-6)
def test_invalid_pdg_code_raises():
with pytest.raises(ValueError):
particle_mass_charge(999999999)
def test_particle_mass_charge_is_cached():
particle_mass_charge.cache_clear()
particle_mass_charge(22)
particle_mass_charge(22)
info = particle_mass_charge.cache_info()
assert info.hits >= 1
def test_particle_phys_array_shape_and_dtype():
arr = particle_phys_array(np.array([22, 11, 2212]))
assert arr.shape == (3, 2)
assert arr.dtype == np.float32
np.testing.assert_allclose(arr[0], [0.0, 0.0])
np.testing.assert_allclose(arr[2], [938.27208943, 1.0], rtol=1e-5)
# ── nearest_known_pdg (reporting-only nearest-neighbour label) ──────────────
def test_nearest_known_pdg_exact_match():
candidates = [22, 11, -11, 2212, 2112]
mass_e, charge_e = particle_mass_charge(11)
result = nearest_known_pdg(np.array([mass_e]), np.array([charge_e]), candidates)
assert result[0] == 11
def test_nearest_known_pdg_prioritises_charge_match():
"""Charge is a small conserved quantum number and should usually match
exactly even when the queried mass is noisy/imperfect."""
candidates = [22, 11, -11, 2212]
# Close to electron mass but not exact, positive charge like the positron.
result = nearest_known_pdg(np.array([0.6]), np.array([1.0]), candidates)
assert result[0] == -11
def test_nearest_known_pdg_empty_candidates_raises():
with pytest.raises(ValueError):
nearest_known_pdg(np.array([1.0]), np.array([0.0]), [])
def test_nearest_known_pdg_shape():
candidates = [22, 11, -11, 2212, 2112]
n = 10
result = nearest_known_pdg(
np.random.default_rng(0).uniform(0, 1000, n),
np.random.default_rng(1).uniform(-1, 1, n),
candidates,
)
assert result.shape == (n,)
assert set(result.tolist()) <= set(candidates)