mirror of
https://github.com/gonum/gonum.git
synced 2025-10-31 18:42:45 +08:00
101 lines
2.7 KiB
Go
101 lines
2.7 KiB
Go
// Copyright ©2017 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"
|
|
"math/rand"
|
|
"testing"
|
|
|
|
"gonum.org/v1/gonum/blas"
|
|
"gonum.org/v1/gonum/blas/blas64"
|
|
"gonum.org/v1/gonum/floats"
|
|
)
|
|
|
|
type Dlags2er interface {
|
|
Dlags2(upper bool, a1, a2, a3, b1, b2, b3 float64) (csu, snu, csv, snv, csq, snq float64)
|
|
}
|
|
|
|
func Dlags2Test(t *testing.T, impl Dlags2er) {
|
|
rnd := rand.New(rand.NewSource(1))
|
|
for _, upper := range []bool{true, false} {
|
|
for i := 0; i < 100; i++ {
|
|
a1 := rnd.Float64()
|
|
a2 := rnd.Float64()
|
|
a3 := rnd.Float64()
|
|
b1 := rnd.Float64()
|
|
b2 := rnd.Float64()
|
|
b3 := rnd.Float64()
|
|
|
|
csu, snu, csv, snv, csq, snq := impl.Dlags2(upper, a1, a2, a3, b1, b2, b3)
|
|
|
|
detU := det2x2(csu, snu, -snu, csu)
|
|
if !floats.EqualWithinAbsOrRel(math.Abs(detU), 1, 1e-14, 1e-14) {
|
|
t.Errorf("U not orthogonal: det(U)=%v", detU)
|
|
}
|
|
detV := det2x2(csv, snv, -snv, csv)
|
|
if !floats.EqualWithinAbsOrRel(math.Abs(detV), 1, 1e-14, 1e-14) {
|
|
t.Errorf("V not orthogonal: det(V)=%v", detV)
|
|
}
|
|
detQ := det2x2(csq, snq, -snq, csq)
|
|
if !floats.EqualWithinAbsOrRel(math.Abs(detQ), 1, 1e-14, 1e-14) {
|
|
t.Errorf("Q not orthogonal: det(Q)=%v", detQ)
|
|
}
|
|
|
|
u := blas64.General{
|
|
Rows: 2,
|
|
Cols: 2,
|
|
Stride: 2,
|
|
Data: []float64{csu, snu, -snu, csu},
|
|
}
|
|
v := blas64.General{
|
|
Rows: 2,
|
|
Cols: 2,
|
|
Stride: 2,
|
|
Data: []float64{csv, snv, -snv, csv},
|
|
}
|
|
q := blas64.General{
|
|
Rows: 2,
|
|
Cols: 2,
|
|
Stride: 2,
|
|
Data: []float64{csq, snq, -snq, csq},
|
|
}
|
|
|
|
a := blas64.General{Rows: 2, Cols: 2, Stride: 2}
|
|
b := blas64.General{Rows: 2, Cols: 2, Stride: 2}
|
|
if upper {
|
|
a.Data = []float64{a1, a2, 0, a3}
|
|
b.Data = []float64{b1, b2, 0, b3}
|
|
} else {
|
|
a.Data = []float64{a1, 0, a2, a3}
|
|
b.Data = []float64{b1, 0, b2, b3}
|
|
}
|
|
|
|
tmp := blas64.General{Rows: 2, Cols: 2, Stride: 2, Data: make([]float64, 4)}
|
|
blas64.Gemm(blas.Trans, blas.NoTrans, 1, u, a, 0, tmp)
|
|
blas64.Gemm(blas.NoTrans, blas.NoTrans, 1, tmp, q, 0, a)
|
|
blas64.Gemm(blas.Trans, blas.NoTrans, 1, v, b, 0, tmp)
|
|
blas64.Gemm(blas.NoTrans, blas.NoTrans, 1, tmp, q, 0, b)
|
|
|
|
var gotA, gotB float64
|
|
if upper {
|
|
gotA = a.Data[1]
|
|
gotB = b.Data[1]
|
|
} else {
|
|
gotA = a.Data[2]
|
|
gotB = b.Data[2]
|
|
}
|
|
if !floats.EqualWithinAbsOrRel(gotA, 0, 1e-14, 1e-14) {
|
|
t.Errorf("unexpected non-zero value for zero triangle of U^T*A*Q: %v", gotA)
|
|
}
|
|
if !floats.EqualWithinAbsOrRel(gotB, 0, 1e-14, 1e-14) {
|
|
t.Errorf("unexpected non-zero value for zero triangle of V^T*B*Q: %v", gotB)
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
func det2x2(a, b, c, d float64) float64 { return a*d - b*c }
|