github.com/gonum/lapack@v0.0.0-20181123203213-e4cdc5a0bff9/testlapack/dorgl2.go (about)

     1  // Copyright ©2015 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.
     4  
     5  package testlapack
     6  
     7  import (
     8  	"math/rand"
     9  	"testing"
    10  
    11  	"github.com/gonum/floats"
    12  )
    13  
    14  type Dorgl2er interface {
    15  	Dgelqfer
    16  	Dorgl2(m, n, k int, a []float64, lda int, tau []float64, work []float64)
    17  }
    18  
    19  func Dorgl2Test(t *testing.T, impl Dorgl2er) {
    20  	rnd := rand.New(rand.NewSource(1))
    21  	for _, test := range []struct {
    22  		m, n, lda int
    23  	}{
    24  		{3, 3, 0},
    25  		{3, 4, 0},
    26  
    27  		{5, 5, 20},
    28  		{5, 10, 20},
    29  	} {
    30  		m := test.m
    31  		n := test.n
    32  		lda := test.lda
    33  		if lda == 0 {
    34  			lda = test.n
    35  		}
    36  		a := make([]float64, m*lda)
    37  		for i := range a {
    38  			a[i] = rnd.NormFloat64()
    39  		}
    40  		k := min(m, n)
    41  		tau := make([]float64, k)
    42  		work := make([]float64, 1)
    43  		impl.Dgelqf(m, n, a, lda, tau, work, -1)
    44  		work = make([]float64, int(work[0]))
    45  		impl.Dgelqf(m, n, a, lda, tau, work, len(work))
    46  
    47  		q := constructQ("LQ", m, n, a, lda, tau)
    48  
    49  		impl.Dorgl2(m, n, k, a, lda, tau, work)
    50  
    51  		// Check that the first m rows match.
    52  		same := true
    53  		for i := 0; i < m; i++ {
    54  			for j := 0; j < n; j++ {
    55  				if !floats.EqualWithinAbsOrRel(q.Data[i*q.Stride+j], a[i*lda+j], 1e-12, 1e-12) {
    56  					same = false
    57  					break
    58  				}
    59  			}
    60  		}
    61  		if !same {
    62  			t.Errorf("Q mismatch")
    63  		}
    64  	}
    65  }