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tono/tests/node_tests/acf_1d.py
2026-03-29 19:13:59 -07:00

73 lines
2.2 KiB
Python

import numpy as np
from backend.data_types import LineData, RecordTable
def test_acf_1d():
from backend.nodes.acf_1d import ACF1D
node = ACF1D()
# Periodic signal — ACF should show a peak at the period
n = 256
period = 32
t = np.arange(n, dtype=np.float64)
signal = np.sin(2 * np.pi * t / period)
profile = LineData(
data=signal,
x_axis=t * 1e-9,
x_unit="m",
y_unit="V",
)
acf, measurement = node.process(profile, level="mean")
assert isinstance(acf, LineData)
assert isinstance(measurement, RecordTable)
# ACF should be symmetric about zero lag
center = len(acf) // 2
assert np.allclose(acf.data, acf.data[::-1], atol=1e-10)
# Peak period should be close to the input period in metres
expected_period_m = period * 1e-9
assert len(measurement) == 1
assert measurement[0]["quantity"] == "Peak period"
assert abs(measurement[0]["value"] - expected_period_m) / expected_period_m < 0.1
assert measurement[0]["unit"] == "m"
# x_axis should be centred on zero
assert acf.x_axis is not None
assert acf.x_axis[center] == 0.0 or abs(acf.x_axis[center]) < 1e-15
# ACF at zero lag should equal variance (signal is mean-subtracted)
assert acf.data[center] > 0
def test_acf_1d_no_peak():
from backend.nodes.acf_1d import ACF1D
node = ACF1D()
# White noise — ACF should have no reliable peak, measurement table may be empty
rng = np.random.default_rng(0)
noise = rng.standard_normal(64)
profile = LineData(data=noise, x_axis=np.arange(64, dtype=np.float64), x_unit="m")
acf, measurement = node.process(profile, level="none")
assert isinstance(acf, LineData)
# measurement is either empty or has one row — no assertion on content
def test_acf_1d_level_none():
from backend.nodes.acf_1d import ACF1D
node = ACF1D()
# With level="none", a DC offset should not be removed
data = np.ones(32, dtype=np.float64) * 5.0
profile = LineData(data=data, x_axis=np.arange(32, dtype=np.float64))
acf, _ = node.process(profile, level="none")
# ACF of a constant is a constant
assert acf.data[len(acf) // 2] > 0