testlapack: add huge and tiny input values to Dlartg test
MODIFY
testlapack/dlartg.go
testlapack/dlartg.go
@@ -8,6 +8,8 @@ import (
"math"
"math/rand"
"testing"
+
+ "github.com/gonum/floats"
)
type Dlartger interface {
@@ -15,22 +17,65 @@ type Dlartger interface {
}
func DlartgTest(t *testing.T, impl Dlartger) {
+ const (
+ tol = 1e-14
+ safmn = 2.002083095183101e-146 // math.Pow(dlamchB, math.Floor(math.Log(safmin/eps)/math.Log(dlamchB)/2))
+ safmx = 4.994797680505588e+145 // 1 / safmn
+ )
rnd := rand.New(rand.NewSource(1))
- for i := 0; i < 100; i++ {
- f := rnd.NormFloat64()
- g := rnd.NormFloat64()
+ for i := 0; i < 1000; i++ {
+ var f float64
+ var fHuge bool
+ switch rnd.Intn(3) {
+ case 0:
+ // Huge f.
+ fHuge = true
+ f = math.Pow(10, 10-20*rnd.Float64()) * safmx
+ case 1:
+ // Tiny f.
+ f = math.Pow(10, 10-20*rnd.Float64()) * safmn
+ default:
+ f = rnd.NormFloat64()
+ }
+ if rnd.Intn(2) == 0 {
+ f *= -1
+ }
+
+ var g float64
+ var gHuge bool
+ switch rnd.Intn(3) {
+ case 0:
+ // Huge g.
+ gHuge = true
+ g = math.Pow(10, 10-20*rnd.Float64()) * safmx
+ case 1:
+ // Tiny g.
+ g = math.Pow(10, 10-20*rnd.Float64()) * safmn
+ default:
+ g = rnd.NormFloat64()
+ }
+ if rnd.Intn(2) == 0 {
+ g *= -1
+ }
+
cs, sn, r := impl.Dlartg(f, g)
- rTest := cs*f + sn*g
+ rWant := cs*f + sn*g
+ if !floats.EqualWithinAbsOrRel(math.Abs(rWant), math.Abs(r), tol, tol) {
+ t.Errorf("Case f=%v,g=%v: unexpected r. Want %v, got %v", f, g, rWant, r)
+ }
+ oneTest := cs*cs + sn*sn
+ if math.Abs(oneTest-1) > tol {
+ t.Errorf("Case f=%v,g=%v: expected cs^2+sn^2==1, got %v", f, g, oneTest)
+ }
+ if !fHuge && !gHuge {
zeroTest := -sn*f + cs*g
- if math.Abs(rTest-r) > 1e-14 {
- t.Errorf("R result mismatch. Computed %v, found %v", r, rTest)
+ if math.Abs(zeroTest) > tol {
+ t.Errorf("Case f=%v,g=%v: expected zero, got %v", f, g, zeroTest)
}
- if math.Abs(zeroTest) > 1e-14 {
- t.Errorf("Zero result mismatch. Found %v", zeroTest)
}
if math.Abs(f) > math.Abs(g) && cs < 0 {
- t.Errorf("Unexpected negative cs %v", cs)
+ t.Errorf("Case f=%v,g=%v: unexpected negative cs %v", f, g, cs)
}
}
for i := 0; i < 100; i++ {

testlapack: add huge and tiny input values to Dlartg test