| // 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 ( |
| "fmt" |
| "math" |
| "testing" |
| |
| "golang.org/x/exp/rand" |
| |
| "gonum.org/v1/gonum/blas" |
| "gonum.org/v1/gonum/floats" |
| "gonum.org/v1/gonum/lapack" |
| ) |
| |
| type Dlantrer interface { |
| Dlanger |
| Dlantr(norm lapack.MatrixNorm, uplo blas.Uplo, diag blas.Diag, m, n int, a []float64, lda int, work []float64) float64 |
| } |
| |
| func DlantrTest(t *testing.T, impl Dlantrer) { |
| rnd := rand.New(rand.NewSource(1)) |
| for _, m := range []int{0, 1, 2, 3, 4, 5, 10} { |
| for _, n := range []int{0, 1, 2, 3, 4, 5, 10} { |
| for _, uplo := range []blas.Uplo{blas.Lower, blas.Upper} { |
| if uplo == blas.Upper && m > n { |
| continue |
| } |
| if uplo == blas.Lower && n > m { |
| continue |
| } |
| for _, diag := range []blas.Diag{blas.NonUnit, blas.Unit} { |
| for _, lda := range []int{max(1, n), n + 3} { |
| dlantrTest(t, impl, rnd, uplo, diag, m, n, lda) |
| } |
| } |
| } |
| } |
| } |
| } |
| |
| func dlantrTest(t *testing.T, impl Dlantrer, rnd *rand.Rand, uplo blas.Uplo, diag blas.Diag, m, n, lda int) { |
| const tol = 1e-14 |
| |
| // Generate a random triangular matrix. If the matrix has unit diagonal, |
| // don't set the diagonal elements to 1. |
| a := make([]float64, max(0, (m-1)*lda+n)) |
| for i := range a { |
| a[i] = rnd.NormFloat64() |
| } |
| rowsum := make([]float64, m) |
| colsum := make([]float64, n) |
| var frobWant, maxabsWant float64 |
| if diag == blas.Unit { |
| // Account for the unit diagonal. |
| for i := 0; i < min(m, n); i++ { |
| rowsum[i] = 1 |
| colsum[i] = 1 |
| } |
| frobWant = float64(min(m, n)) |
| if min(m, n) > 0 { |
| maxabsWant = 1 |
| } |
| } |
| if uplo == blas.Upper { |
| for i := 0; i < min(m, n); i++ { |
| start := i |
| if diag == blas.Unit { |
| start = i + 1 |
| } |
| for j := start; j < n; j++ { |
| aij := 2*rnd.Float64() - 1 |
| a[i*lda+j] = aij |
| rowsum[i] += math.Abs(aij) |
| colsum[j] += math.Abs(aij) |
| maxabsWant = math.Max(maxabsWant, math.Abs(aij)) |
| frobWant += aij * aij |
| } |
| } |
| } else { |
| for i := 0; i < m; i++ { |
| end := i |
| if diag == blas.Unit { |
| end = i - 1 |
| } |
| for j := 0; j <= min(end, n-1); j++ { |
| aij := 2*rnd.Float64() - 1 |
| a[i*lda+j] = aij |
| rowsum[i] += math.Abs(aij) |
| colsum[j] += math.Abs(aij) |
| maxabsWant = math.Max(maxabsWant, math.Abs(aij)) |
| frobWant += aij * aij |
| } |
| } |
| } |
| frobWant = math.Sqrt(frobWant) |
| var maxcolsumWant, maxrowsumWant float64 |
| if n > 0 { |
| maxcolsumWant = floats.Max(colsum) |
| } |
| if m > 0 { |
| maxrowsumWant = floats.Max(rowsum) |
| } |
| |
| aCopy := make([]float64, len(a)) |
| copy(aCopy, a) |
| |
| for _, norm := range []lapack.MatrixNorm{lapack.MaxAbs, lapack.MaxColumnSum, lapack.MaxRowSum, lapack.Frobenius} { |
| name := fmt.Sprintf("norm=%v,uplo=%v,diag=%v,m=%v,n=%v,lda=%v", string(norm), string(uplo), string(diag), m, n, lda) |
| |
| var work []float64 |
| if norm == lapack.MaxColumnSum { |
| work = make([]float64, n) |
| } |
| normGot := impl.Dlantr(norm, uplo, diag, m, n, a, lda, work) |
| |
| if !floats.Equal(a, aCopy) { |
| t.Fatalf("%v: unexpected modification of a", name) |
| } |
| |
| if norm == lapack.MaxAbs { |
| // MaxAbs norm involves no floating-point computation, |
| // so we expect exact equality here. |
| if normGot != maxabsWant { |
| t.Errorf("%v: unexpected result; got %v, want %v", name, normGot, maxabsWant) |
| } |
| continue |
| } |
| |
| var normWant float64 |
| switch norm { |
| case lapack.MaxColumnSum: |
| normWant = maxcolsumWant |
| case lapack.MaxRowSum: |
| normWant = maxrowsumWant |
| case lapack.Frobenius: |
| normWant = frobWant |
| } |
| if math.Abs(normGot-normWant) >= tol { |
| t.Errorf("%v: unexpected result; got %v, want %v", name, normGot, normWant) |
| } |
| } |
| } |