dwt_transform — MATH transform op

• Data kinds: image2d → table

• Call: import fullseye as fs; fs.ledger.dwt_transform(x, *, order: 'int' = 2, levels: 'int' = 1, axes=None) -> 'dict' (to call the implementation directly, import mathtransforms; mathtransforms.dwt_transform(x, *, order: 'int' = 2, levels: 'int' = 1, axes=None) -> 'dict'; from the registry, opsmath.get("dwt_transform"))

Usage

Multi-level, N-dimensional discrete wavelet transform with Daubechies dbN (exactly orthonormal with periodic boundaries).

Args:

x: real array (1-D signal, 2-D image, 3-D volume). The length of each transformed axis is a multiple of 2^levels.

order: the N of dbN (1 = Haar).

levels: number of levels. At each level the approximation (low-pass on all axes) is split further.

axes: axes to transform (all axes if omitted).

Returns:

approx the final approximation, details = a dict per level (keys are the sequence of 'a'/'d' per axis, e.g. for 2-D 'ad', 'da', 'dd'), energy_in, energy_out (equal by Parseval), order, levels, axes. Passing the whole result to dwt_inverse reconstructs the original.

Family-wide input contract (fail-closed)

Every mathops op validates its input before computing (nothing slips through silently):

• complex input raises ValueError — coercing to float64 silently discards the imaginary part (numpy only emits a ComplexWarning and returns a plausible-looking wrong real number). State .real/.imag/abs() explicitly, or use complexops, which handles complex data.

• masked arrays with masked elements raise ValueError — the implicit conversion that peels off the mask and uses the raw values underneath is refused. Say explicitly whether to fill or to drop.

• NaN/Inf raises ValueError on every input (refused with the count stated — it propagates through the whole result).

• Shapes are strict: 1-D and 2-D are never implicitly promoted or broadcast (a matrix in a vector slot, or a vector in a matrix slot, raises ValueError; reshape explicitly).

• Size cap: ops that take a matrix, and the stat_histogram bins, raise ValueError beyond mathops.MAX_ELEMENTS (2^26 ≈ 67 million elements).

Detailed usage guide

• math_metrology family guide

References (sample data, literature)

• Sample-data catalog (download URLs / licences) — 2-D uses skimage.data (BSD/public domain) plus synthetic images; 3-D lists download URLs for real data sources (Stanford, PDS, …).

• Operator provenance and references — the sources of the research/methods this op family came from.

• The canonical algorithm (author, year) and its uses are named in the family usage guide above.

Runnable examples (verified samples that actually call this op)

• transforms_tour — py -3.11 examples/transforms_tour.py

Ops the type connects to (they accept table as input)

dynsys_poincare_section · dwt_inverse · chebyshev_eval_nd

Same category (transform)

abel_transform · abel_inverse · abel_inverse_image · abel_revolve · hankel_transform · tf_poles_zeros · tf_freq_response · tf_impulse_response


*Provenance: mathtransforms.py — MATH operator registry. This per-op note is generated by tools/opdocs.py md (do not hand-edit).*

© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.