algebra op• Data kinds: matrix → rot_scale
• Call: import fullseye as fs; fs.ledger.matrix_to_rot_scale(matrix) (to call the implementation directly, import reprconv; reprconv.matrix_to_rot_scale(matrix); from the registry, opsreprconv.get("matrix_to_rot_scale"))
A 2-D similarity transform (2,2) → (angle [deg], scale). The inverse of rot_scale_to_matrix.
The scale is the column norm, the angle is atan2(m[1,0], m[0,0]). Passing a general (2,2) that contains shear raises no exception (only the similarity part is read), so when you need a residual, compute m - rot_scale_to_matrix(...) on the caller's side.
Args:
matrix: (2, 2).
Returns:
2-tuple of float (angle_deg, scale).
Raises:
ValueError: not (2,2) / degenerate (scale 0) / non-finite.
• 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.
• representation_conversion — py -3.11 examples/representation_conversion.py
rot_scale as input)algebra)angle_to_matrix · matrix_to_angle · rot_scale_to_matrix · shift_to_vector · vector_to_shift · cscalar_to_polar · polar_to_cscalar · countrate_to_counts
*Provenance: reprconv.py — REPRCONV 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.