linalg op• Data kinds: matrix → matrix
• Call: import mathops; mathops.mat_pinv(a, rcond=1e-12) (or opsmath.get("mat_pinv"))
Moore-Penrose pseudo-inverse via SVD, with the cutoff explicit.
Singular values below `rcond * s_max` are treated as zero — that cutoff
*is* the regularisation, so it is a named, documented parameter here
(default `1e-12`) rather than a hidden library default: raising it
discards noisy directions (stabler, more biased), lowering it keeps them
(exact for well-conditioned *A*, explosive near rank deficiency).
Works for any `(m, n): pinv(A) @ b` is the least-squares solution for
`m > n and the minimum-norm solution for m < n`.
HALCON: no direct operator — HALCON reaches the same result through
`svd_matrix` + reciprocal singular values.
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).
• blas_threads_and_memory — 行列分解が遅い理由の知識 — BLAS スレッド・キャッシュ・メモリ配置
• 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.
• math_metrology — py -3.11 examples/math_metrology.py
matrix as input)mat_solve · mat_lstsq · mat_svd · mat_eigh · mat_cond · stat_covariance · stat_correlation
linalg)mat_solve · mat_lstsq · mat_svd · mat_eigh · mat_cond
*Provenance: mathops.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.