mirror of
https://github.com/gonum/gonum.git
synced 2025-10-05 15:16:59 +08:00
cf3307fa63
This is not intended to be a completed transition since it leaves the libraries unusable to external client code, but rather as a step towards use of math/rand/v2. This initial step allows repair of sequence change failures without having to worry about API difference.
51 lines
1.4 KiB
Go
51 lines
1.4 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 (
|
||
"testing"
|
||
|
||
"gonum.org/v1/gonum/floats/scalar"
|
||
"gonum.org/v1/gonum/internal/rand"
|
||
"gonum.org/v1/gonum/lapack"
|
||
)
|
||
|
||
type Dlapller interface {
|
||
Dgesvder
|
||
Dlapll(n int, x []float64, incX int, y []float64, incY int) float64
|
||
}
|
||
|
||
func DlapllTest(t *testing.T, impl Dlapller) {
|
||
rnd := rand.New(rand.NewSource(1))
|
||
for i, m := range []int{5, 6, 9, 300, 400, 600} {
|
||
n := 2
|
||
lda := n
|
||
// Allocate m×2 matrix A and fill it with random numbers.
|
||
a := make([]float64, m*lda)
|
||
for i := range a {
|
||
a[i] = rnd.NormFloat64()
|
||
}
|
||
// Store a copy of A for later comparison.
|
||
aCopy := make([]float64, len(a))
|
||
copy(aCopy, a)
|
||
|
||
// Compute the smallest singular value of A.
|
||
got := impl.Dlapll(m, a[0:], lda, a[1:], lda)
|
||
|
||
// Compute singular values of A independently by Dgesvd.
|
||
s := make([]float64, min(m, n))
|
||
work := make([]float64, 1)
|
||
impl.Dgesvd(lapack.SVDNone, lapack.SVDNone, m, n, aCopy, lda, s, nil, 1, nil, 1, work, -1)
|
||
work = make([]float64, int(work[0]))
|
||
impl.Dgesvd(lapack.SVDNone, lapack.SVDNone, m, n, aCopy, lda, s, nil, 1, nil, 1, work, len(work))
|
||
// Take the smallest singular value.
|
||
want := s[len(s)-1]
|
||
|
||
if !scalar.EqualWithinAbsOrRel(got, want, 1e-14, 1e-14) {
|
||
t.Errorf("Case %d: unexpected smallest singular value, got:%f want:%f", i, got, want)
|
||
}
|
||
}
|
||
}
|