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80 lines
1.7 KiB
Go
80 lines
1.7 KiB
Go
// Copyright ©2015 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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"testing"
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"golang.org/x/exp/rand"
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"gonum.org/v1/gonum/floats/scalar"
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)
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type Dorg2rer interface {
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Dgeqrfer
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Dorg2r(m, n, k int, a []float64, lda int, tau []float64, work []float64)
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}
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func Dorg2rTest(t *testing.T, impl Dorg2rer) {
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rnd := rand.New(rand.NewSource(1))
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for ti, test := range []struct {
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m, n, k, lda int
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}{
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{3, 3, 0, 0},
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{4, 3, 0, 0},
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{3, 3, 2, 0},
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{4, 3, 2, 0},
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{5, 5, 0, 20},
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{5, 5, 3, 20},
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{10, 5, 0, 20},
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{10, 5, 2, 20},
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} {
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m := test.m
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n := test.n
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lda := test.lda
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if lda == 0 {
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lda = test.n
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}
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// Allocate m×n matrix A and fill it with random numbers.
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a := make([]float64, m*lda)
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for i := range a {
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a[i] = rnd.NormFloat64()
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}
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// Compute the QR decomposition of A.
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tau := make([]float64, min(m, n))
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work := make([]float64, 1)
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impl.Dgeqrf(m, n, a, lda, tau, work, -1)
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work = make([]float64, int(work[0]))
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impl.Dgeqrf(m, n, a, lda, tau, work, len(work))
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// Compute the matrix Q explicitly using the first k elementary reflectors.
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k := test.k
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if k == 0 {
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k = n
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}
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q := constructQK("QR", m, n, k, a, lda, tau)
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// Compute the matrix Q using Dorg2r.
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impl.Dorg2r(m, n, k, a, lda, tau, work)
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// Check that the first n columns of both results match.
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same := true
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loop:
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for i := 0; i < m; i++ {
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for j := 0; j < n; j++ {
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if !scalar.EqualWithinAbsOrRel(q.Data[i*q.Stride+j], a[i*lda+j], 1e-12, 1e-12) {
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same = false
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break loop
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}
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}
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}
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if !same {
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t.Errorf("Case %v: Q mismatch", ti)
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}
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}
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}
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