At pad 40 the old path materialised a ~9 GB padded spectrum per row,
which collapsed the chunk planner to one worker and one rfft call with
workers=1 — synthesis ran single-threaded, ~1 hour per angle on real
files.
The padded spectrum is never materialised now. Each block of 512
waveforms gets a coarse rfft at next_fast_len(2*spf); every coarse bin
within 0.7 of its row's max (plus the DC-adjacent window, which coarse
DC suppression would otherwise blind) is refined onto the exact n_fft
grid by a small complex gemm. The selected bin is bit-identical to the
full padded argmax — enforced by test_zoom_identity, a 25-seed fuzz
test over adversarial spectra, and a clean golden-hash diff against the
pre-rewrite baseline across pads {1,2,4,8,40}, masked/unmasked, bg
on/off, int8/int16, and both backends.
Blocks fan out over a persistent thread pool; pyFFTW runs through
per-thread FFTW_MEASURE builder plans with wisdom persisted to
~/.cache/sras-viewer, and threadpoolctl clamps BLAS under the pool.
compute_rf_image(exact=True) (or SRAS_FFT_EXACT=1) keeps the reference
padded path for audits.
tools/bench_fft.py measures: pad 40, 16 cores, 8192x2500 synthetic —
exact serial 717 wf/s -> zoom pool 25100 wf/s (35x, pyFFTW backend;
19x scipy), every variant verified equal to the reference.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
- pyproject.toml replaces sras_viewer_requirements.txt (same pins) and
adds a dev extra with pytest.
- tools/test_refactor.py, test_alignment.py, test_gui.py become
tests/test_compute.py, tests/test_alignment.py, tests/test_gui.py with
assertions preserved verbatim. test_gui.py stays one ordered
integration sequence over a shared module-scoped window.
- check_equivalence.py: drop the dead pre-refactor monolith shim (and the
_compute_angle_alignment alias it consumed), extend the pad sweep to
(1, 2, 4, 8, 40), add legacy-v4 and big-endian int16 legs (new bps=2
option in make_test_sras) so the padded FFT path and the >i2 memmap
path are in the baseline before the FFT rewrite.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Thomas Ales