local copy of Dlapy2Test

lapack/netlib/lapack_test.go

@@ -9,6 +9,8 @@ import (
 
 	"gonum.org/v1/gonum/blas"
 	"gonum.org/v1/gonum/lapack/testlapack"
+
+	testlpck "gonum.org/v1/netlib/lapack/netlib/testlapack"
 )
 
 var impl = Implementation{}
@@ -93,7 +95,7 @@ func TestDlapmt(t *testing.T) {
 }
 
 func TestDlapy2(t *testing.T) {
-	testlapack.Dlapy2Test(t, impl)
+	testlpck.Dlapy2Test(t, impl)
 }
 
 func TestDlarfx(t *testing.T) {

lapack/netlib/testlapack/dlapy2.go

@@ -0,0 +1,32 @@
+// Copyright ©2016 The Gonum Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package testlapack
+
+import (
+	"math"
+	"testing"
+
+	"golang.org/x/exp/rand"
+
+	"gonum.org/v1/gonum/floats/scalar"
+)
+
+type Dlapy2er interface {
+	Dlapy2(float64, float64) float64
+}
+
+func Dlapy2Test(t *testing.T, impl Dlapy2er) {
+	t.Log("local test for Dlapy2")
+	rnd := rand.New(rand.NewSource(1))
+	for i := 0; i < 10; i++ {
+		x := math.Abs(1e200 * rnd.NormFloat64())
+		y := math.Abs(1e200 * rnd.NormFloat64())
+		got := impl.Dlapy2(x, y)
+		want := math.Hypot(x, y)
+		if !scalar.EqualWithinRel(got, want, 1e-15) {
+			t.Errorf("Dlapy2(%g, %g) = %g, want %g", x, y, got, want)
+		}
+	}
+}