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[bytom/vapor.git] / vendor / gonum.org / v1 / gonum / lapack / testlapack / dlange.go

diff --git a/vendor/gonum.org/v1/gonum/lapack/testlapack/dlange.go b/vendor/gonum.org/v1/gonum/lapack/testlapack/dlange.go
new file mode 100644 (file)
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+++ b/vendor/gonum.org/v1/gonum/lapack/testlapack/dlange.go
@@ -0,0 +1,94 @@
+// Copyright ©2015 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 (
+       "math"
+       "testing"
+
+       "golang.org/x/exp/rand"
+
+       "gonum.org/v1/gonum/blas/blas64"
+       "gonum.org/v1/gonum/lapack"
+)
+
+type Dlanger interface {
+       Dlange(norm lapack.MatrixNorm, m, n int, a []float64, lda int, work []float64) float64
+}
+
+func DlangeTest(t *testing.T, impl Dlanger) {
+       rnd := rand.New(rand.NewSource(1))
+       for _, test := range []struct {
+               m, n, lda int
+       }{
+               {4, 3, 0},
+               {3, 4, 0},
+               {4, 3, 100},
+               {3, 4, 100},
+       } {
+               m := test.m
+               n := test.n
+               lda := test.lda
+               if lda == 0 {
+                       lda = n
+               }
+               a := make([]float64, m*lda)
+               for i := range a {
+                       a[i] = rnd.Float64() - 0.5
+               }
+               work := make([]float64, n)
+               for i := range work {
+                       work[i] = rnd.Float64()
+               }
+               aCopy := make([]float64, len(a))
+               copy(aCopy, a)
+
+               // Test MaxAbs norm.
+               norm := impl.Dlange(lapack.MaxAbs, m, n, a, lda, work)
+               var ans float64
+               for i := 0; i < m; i++ {
+                       idx := blas64.Iamax(n, blas64.Vector{Inc: 1, Data: aCopy[i*lda:]})
+                       ans = math.Max(ans, math.Abs(a[i*lda+idx]))
+               }
+               // Should be strictly equal because there is no floating point summation error.
+               if ans != norm {
+                       t.Errorf("MaxAbs mismatch. Want %v, got %v.", ans, norm)
+               }
+
+               // Test MaxColumnSum norm.
+               norm = impl.Dlange(lapack.MaxColumnSum, m, n, a, lda, work)
+               ans = 0
+               for i := 0; i < n; i++ {
+                       sum := blas64.Asum(m, blas64.Vector{Inc: lda, Data: aCopy[i:]})
+                       ans = math.Max(ans, sum)
+               }
+               if math.Abs(norm-ans) > 1e-14 {
+                       t.Errorf("MaxColumnSum mismatch. Want %v, got %v.", ans, norm)
+               }
+
+               // Test MaxRowSum norm.
+               norm = impl.Dlange(lapack.MaxRowSum, m, n, a, lda, work)
+               ans = 0
+               for i := 0; i < m; i++ {
+                       sum := blas64.Asum(n, blas64.Vector{Inc: 1, Data: aCopy[i*lda:]})
+                       ans = math.Max(ans, sum)
+               }
+               if math.Abs(norm-ans) > 1e-14 {
+                       t.Errorf("MaxRowSum mismatch. Want %v, got %v.", ans, norm)
+               }
+
+               // Test Frobenius norm
+               norm = impl.Dlange(lapack.NormFrob, m, n, a, lda, work)
+               ans = 0
+               for i := 0; i < m; i++ {
+                       sum := blas64.Nrm2(n, blas64.Vector{Inc: 1, Data: aCopy[i*lda:]})
+                       ans += sum * sum
+               }
+               ans = math.Sqrt(ans)
+               if math.Abs(norm-ans) > 1e-14 {
+                       t.Errorf("NormFrob mismatch. Want %v, got %v.", ans, norm)
+               }
+       }
+}