| // 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" |
| "math/rand" |
| "testing" |
| |
| "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) |
| } |
| } |
| } |