github.com/gonum/lapack@v0.0.0-20181123203213-e4cdc5a0bff9/testlapack/dlapy2.go (about)

     1  // Copyright ©2016 The gonum Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package testlapack
     6  
     7  import (
     8  	"math"
     9  	"math/rand"
    10  	"testing"
    11  
    12  	"github.com/gonum/floats"
    13  )
    14  
    15  type Dlapy2er interface {
    16  	Dlapy2(float64, float64) float64
    17  }
    18  
    19  func Dlapy2Test(t *testing.T, impl Dlapy2er) {
    20  	rnd := rand.New(rand.NewSource(1))
    21  	for i := 0; i < 10; i++ {
    22  		x := math.Abs(1e200 * rnd.NormFloat64())
    23  		y := math.Abs(1e200 * rnd.NormFloat64())
    24  		got := impl.Dlapy2(x, y)
    25  		want := math.Hypot(x, y)
    26  		if !floats.EqualWithinRel(got, want, 1e-16) {
    27  			t.Errorf("Dlapy2(%g, %g) = %g, want %g", x, y, got, want)
    28  		}
    29  	}
    30  }