feat: initial release

Assisted-by: GLM 5.3 Flash

linalg/helpers.go

@@ -0,0 +1,59 @@
+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: MIT
+
+package linalg
+
+import (
+	"math"
+	"math/cmplx"
+
+	"sourcedock.dev/petrbalvin/tensor/internal/base"
+	"sourcedock.dev/petrbalvin/tensor/internal/core"
+)
+
+// scalar is the element type the generic kernels serve.
+type scalar interface {
+	float64 | complex128
+}
+
+// absComplex returns |z|, the shared magnitude used for tolerances.
+func absComplex(z complex128) float64 { return base.AbsComplex(z) }
+
+func absOf[T scalar](v T) float64 {
+	switch x := any(v).(type) {
+	case float64:
+		return math.Abs(x)
+	case complex128:
+		return cmplx.Abs(x)
+	}
+	return 0
+}
+
+// zeros allocates a zeroed array for internally derived shapes. The
+// error is part of the signature on purpose: a caller whose shape is
+// not provably valid must propagate the failure, not nil-deref.
+func zeros(dt core.Dtype, shape []int) (*core.Array, error) {
+	return core.Zeros(dt, shape...)
+}
+
+// finiteF64 reports whether v is neither NaN nor infinite.
+func finiteF64(v float64) bool { return !math.IsNaN(v) && !math.IsInf(v, 0) }
+
+// vecFinite reports whether every entry of v is finite.
+func vecFinite(v []float64) bool {
+	for _, x := range v {
+		if !finiteF64(x) {
+			return false
+		}
+	}
+	return true
+}
+
+// isRealDtype reports whether a holds real (non-complex) numeric data.
+func isRealDtype(a *core.Array) bool {
+	switch a.Dtype() {
+	case core.Float, core.Float32, core.Int:
+		return true
+	}
+	return false
+}