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.
10 "golang.org/x/exp/rand"
12 "gonum.org/v1/gonum/blas"
13 "gonum.org/v1/gonum/blas/blas64"
14 "gonum.org/v1/gonum/floats"
15 "gonum.org/v1/gonum/lapack"
18 type Dsyever interface {
19 Dsyev(jobz lapack.EVJob, uplo blas.Uplo, n int, a []float64, lda int, w, work []float64, lwork int) (ok bool)
22 func DsyevTest(t *testing.T, impl Dsyever) {
23 rnd := rand.New(rand.NewSource(1))
24 for _, uplo := range []blas.Uplo{blas.Lower, blas.Upper} {
25 for _, test := range []struct {
40 for cas := 0; cas < 10; cas++ {
46 a := make([]float64, n*lda)
48 a[i] = rnd.NormFloat64()
50 aCopy := make([]float64, len(a))
52 w := make([]float64, n)
54 w[i] = rnd.NormFloat64()
57 work := make([]float64, 1)
58 impl.Dsyev(lapack.ComputeEV, uplo, n, a, lda, w, work, -1)
59 work = make([]float64, int(work[0]))
60 impl.Dsyev(lapack.ComputeEV, uplo, n, a, lda, w, work, len(work))
62 // Check that the decomposition is correct
63 orig := blas64.General{
67 Data: make([]float64, n*n),
69 if uplo == blas.Upper {
70 for i := 0; i < n; i++ {
71 for j := i; j < n; j++ {
73 orig.Data[i*orig.Stride+j] = v
74 orig.Data[j*orig.Stride+i] = v
78 for i := 0; i < n; i++ {
79 for j := 0; j <= i; j++ {
81 orig.Data[i*orig.Stride+j] = v
82 orig.Data[j*orig.Stride+i] = v
94 if !eigenDecompCorrect(w, orig, V) {
95 t.Errorf("Decomposition mismatch")
98 // Check that the decomposition is correct when the eigenvectors
100 wAns := make([]float64, len(w))
106 for i := range work {
107 work[i] = rnd.Float64()
109 impl.Dsyev(lapack.None, uplo, n, a, lda, w, work, len(work))
110 if !floats.EqualApprox(w, wAns, 1e-8) {
111 t.Errorf("Eigenvalue mismatch when vectors not computed")