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100 lines
2.5 KiB
Go
100 lines
2.5 KiB
Go
// Copyright ©2016 The gonum Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package testlapack
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import (
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"fmt"
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"math"
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"math/rand"
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"testing"
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"gonum.org/v1/gonum/blas"
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"gonum.org/v1/gonum/blas/blas64"
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)
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type Dorghrer interface {
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Dorghr(n, ilo, ihi int, a []float64, lda int, tau, work []float64, lwork int)
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Dgehrder
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}
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func DorghrTest(t *testing.T, impl Dorghrer) {
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rnd := rand.New(rand.NewSource(1))
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for _, n := range []int{1, 2, 3, 4, 5, 6, 7, 8, 23, 34} {
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for _, extra := range []int{0, 1, 13} {
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for _, optwork := range []bool{true, false} {
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for cas := 0; cas < 100; cas++ {
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ilo := rnd.Intn(n)
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ihi := rnd.Intn(n)
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if ilo > ihi {
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ilo, ihi = ihi, ilo
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}
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testDorghr(t, impl, n, ilo, ihi, extra, optwork, rnd)
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}
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}
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}
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}
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testDorghr(t, impl, 0, 0, -1, 0, false, rnd)
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testDorghr(t, impl, 0, 0, -1, 0, true, rnd)
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}
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func testDorghr(t *testing.T, impl Dorghrer, n, ilo, ihi, extra int, optwork bool, rnd *rand.Rand) {
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const tol = 1e-14
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// Construct the matrix A with elementary reflectors and scalar factors tau.
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a := randomGeneral(n, n, n+extra, rnd)
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var tau []float64
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if n > 1 {
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tau = nanSlice(n - 1)
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}
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work := nanSlice(max(1, n)) // Minimum work for Dgehrd.
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impl.Dgehrd(n, ilo, ihi, a.Data, a.Stride, tau, work, len(work))
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// Extract Q for later comparison.
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q := eye(n, n)
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qCopy := cloneGeneral(q)
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for j := ilo; j < ihi; j++ {
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h := eye(n, n)
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v := blas64.Vector{
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Inc: 1,
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Data: make([]float64, n),
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}
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v.Data[j+1] = 1
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for i := j + 2; i < ihi+1; i++ {
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v.Data[i] = a.Data[i*a.Stride+j]
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}
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blas64.Ger(-tau[j], v, v, h)
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copy(qCopy.Data, q.Data)
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blas64.Gemm(blas.NoTrans, blas.NoTrans, 1, qCopy, h, 0, q)
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}
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if optwork {
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work = nanSlice(1)
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impl.Dorghr(n, ilo, ihi, a.Data, a.Stride, tau, work, -1)
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work = nanSlice(int(work[0]))
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} else {
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work = nanSlice(max(1, ihi-ilo))
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}
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impl.Dorghr(n, ilo, ihi, a.Data, a.Stride, tau, work, len(work))
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prefix := fmt.Sprintf("Case n=%v, ilo=%v, ihi=%v, extra=%v, optwork=%v", n, ilo, ihi, extra, optwork)
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if !generalOutsideAllNaN(a) {
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t.Errorf("%v: out-of-range write to A\n%v", prefix, a.Data)
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}
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if !isOrthonormal(a) {
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t.Errorf("%v: A is not orthogonal\n%v", prefix, a.Data)
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}
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for i := 0; i < n; i++ {
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for j := 0; j < n; j++ {
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aij := a.Data[i*a.Stride+j]
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qij := q.Data[i*q.Stride+j]
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if math.Abs(aij-qij) > tol {
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t.Errorf("%v: unexpected value of A[%v,%v]. want %v, got %v", prefix, i, j, qij, aij)
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}
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}
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}
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}
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