vendor/gonum.org/v1/gonum/lapack/testlapack/dlanst.go

   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.
   4
   5 package testlapack
   6
   7 import (
   8         "math"
   9         "testing"
  10
  11         "golang.org/x/exp/rand"
  12
  13         "gonum.org/v1/gonum/lapack"
  14 )
  15
  16 type Dlanster interface {
  17         Dlanst(norm lapack.MatrixNorm, n int, d, e []float64) float64
  18         Dlanger
  19 }
  20
  21 func DlanstTest(t *testing.T, impl Dlanster) {
  22         rnd := rand.New(rand.NewSource(1))
  23         for _, norm := range []lapack.MatrixNorm{lapack.MaxAbs, lapack.MaxColumnSum, lapack.MaxRowSum, lapack.NormFrob} {
  24                 for _, n := range []int{1, 3, 10, 100} {
  25                         for cas := 0; cas < 100; cas++ {
  26                                 d := make([]float64, n)
  27                                 for i := range d {
  28                                         d[i] = rnd.NormFloat64()
  29                                 }
  30                                 e := make([]float64, n-1)
  31                                 for i := range e {
  32                                         e[i] = rnd.NormFloat64()
  33                                 }
  34
  35                                 m := n
  36                                 lda := n
  37                                 a := make([]float64, m*lda)
  38                                 for i := 0; i < n; i++ {
  39                                         a[i*lda+i] = d[i]
  40                                 }
  41                                 for i := 0; i < n-1; i++ {
  42                                         a[i*lda+i+1] = e[i]
  43                                         a[(i+1)*lda+i] = e[i]
  44                                 }
  45                                 work := make([]float64, n)
  46                                 syNorm := impl.Dlanst(norm, n, d, e)
  47                                 geNorm := impl.Dlange(norm, m, n, a, lda, work)
  48                                 if math.Abs(syNorm-geNorm) > 1e-12 {
  49                                         t.Errorf("Norm mismatch: norm = %v, cas = %v, n = %v. Want %v, got %v.", string(norm), cas, n, geNorm, syNorm)
  50                                 }
  51                         }
  52                 }
  53         }
  54 }