feat: initial release

Assisted-by: GLM 5.3 Flash

linalg/det_factor_dispatch_test.go

@@ -0,0 +1,34 @@
+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: MIT
+
+package linalg
+
+import (
+	"math"
+	"testing"
+)
+
+// TestDetFactorsThroughParallelDispatch drives base.Factor's rank-1
+// update dispatch through the public Det entry: a 200 by 200 upper
+// triangular matrix keeps every pivot on the diagonal, and the first
+// pivot's update spans 199 rows times 200 columns, past the dispatch
+// quantum, so the crewed path runs rather than the inline one. No row
+// changes under the elimination, since the multiplier of every row is
+// zero, so the determinant is exactly 2 to the 200th, which float64
+// holds as an exact power of two.
+func TestDetFactorsThroughParallelDispatch(t *testing.T) {
+	const n = 200
+	vals := make([]float64, n*n)
+	for i := range n {
+		for j := i; j < n; j++ {
+			vals[i*n+j] = 2
+		}
+	}
+	d, err := Det(mustFloats(t, vals, n, n))
+	if err != nil {
+		t.Fatalf("Det: %v", err)
+	}
+	if want := math.Ldexp(1, 200); d != want {
+		t.Fatalf("Det = %v, want exactly %v", d, want)
+	}
+}