| // Copyright ©2017 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 ( |
| "testing" |
| |
| "golang.org/x/exp/rand" |
| |
| "gonum.org/v1/gonum/blas/blas64" |
| ) |
| |
| func TestDlagsy(t *testing.T) { |
| const tol = 1e-14 |
| rnd := rand.New(rand.NewSource(1)) |
| for _, n := range []int{0, 1, 2, 3, 4, 5, 10, 50} { |
| for _, lda := range []int{0, 2*n + 1} { |
| if lda == 0 { |
| lda = max(1, n) |
| } |
| // D is the identity matrix I. |
| d := make([]float64, n) |
| for i := range d { |
| d[i] = 1 |
| } |
| // Allocate an n×n symmetric matrix A and fill it with NaNs. |
| a := nanSlice(n * lda) |
| work := make([]float64, 2*n) |
| // Compute A = U * D * Uᵀ where U is a random orthogonal matrix. |
| Dlagsy(n, 0, d, a, lda, rnd, work) |
| // A should be the identity matrix because |
| // A = U * D * Uᵀ = U * I * Uᵀ = U * Uᵀ = I. |
| dist := distFromIdentity(n, a, lda) |
| if dist > tol { |
| t.Errorf("Case n=%v,lda=%v: |A-I|=%v is too large", n, lda, dist) |
| } |
| } |
| } |
| } |
| |
| func TestDlagge(t *testing.T) { |
| const tol = 1e-14 |
| rnd := rand.New(rand.NewSource(1)) |
| for _, n := range []int{0, 1, 2, 3, 4, 5, 10, 50} { |
| for _, lda := range []int{0, 2*n + 1} { |
| if lda == 0 { |
| lda = max(1, n) |
| } |
| d := make([]float64, n) |
| for i := range d { |
| d[i] = 1 |
| } |
| a := blas64.General{ |
| Rows: n, |
| Cols: n, |
| Stride: lda, |
| Data: nanSlice(n * lda), |
| } |
| work := make([]float64, a.Rows+a.Cols) |
| |
| Dlagge(a.Rows, a.Cols, 0, 0, d, a.Data, a.Stride, rnd, work) |
| |
| if resid := residualOrthogonal(a, false); resid > tol { |
| t.Errorf("Case n=%v,lda=%v: unexpected result", n, lda) |
| } |
| } |
| } |
| } |
| |
| func TestRandomOrthogonal(t *testing.T) { |
| const tol = 1e-14 |
| rnd := rand.New(rand.NewSource(1)) |
| for n := 1; n <= 20; n++ { |
| q := randomOrthogonal(n, rnd) |
| if resid := residualOrthogonal(q, false); resid > tol { |
| t.Errorf("Case n=%v: Q not orthogonal; resid=%v, want<=%v", n, resid, tol) |
| } |
| } |
| } |