feat: initial release

Assisted-by: GLM 5.3 Flash

linalg/fitpoly_test.go

@@ -0,0 +1,33 @@
+// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
+// SPDX-License-Identifier: MIT
+
+package linalg
+
+import (
+	"math"
+	"testing"
+
+	"sourcedock.dev/petrbalvin/tensor/internal/core"
+)
+
+// TestFitEvaluatePolynomial moved with FitPolynomial from the root
+// package: a quadratic fit of y = 2 + x must recover it perfectly.
+func TestFitEvaluatePolynomial(t *testing.T) {
+	x := mustFloats(t, []float64{0, 1, 2}, 3)
+	y := mustFloats(t, []float64{2, 3, 4}, 3)
+	coeffs, err := FitPolynomial(x, y, 1)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if math.Abs(coeffs.FloatAt(0)-2) > 1e-9 || math.Abs(coeffs.FloatAt(1)-1) > 1e-9 {
+		t.Errorf("poly coeffs: %v", coeffs.RawFloats())
+	}
+	q, _ := core.FromFloats([]float64{5, 7}, 2)
+	out, err := core.EvaluatePolynomial(coeffs, q)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if math.Abs(out.FloatAt(0)-7) > 1e-9 || math.Abs(out.FloatAt(1)-9) > 1e-9 {
+		t.Errorf("poly eval: %v", out.RawFloats())
+	}
+}