| // 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" |
| "gonum.org/v1/gonum/blas/blas64" |
| "gonum.org/v1/gonum/floats" |
| ) |
| |
| type Dtrti2er interface { |
| Dtrti2(uplo blas.Uplo, diag blas.Diag, n int, a []float64, lda int) |
| } |
| |
| func Dtrti2Test(t *testing.T, impl Dtrti2er) { |
| const tol = 1e-14 |
| for _, test := range []struct { |
| a []float64 |
| n int |
| uplo blas.Uplo |
| diag blas.Diag |
| ans []float64 |
| }{ |
| { |
| a: []float64{ |
| 2, 3, 4, |
| 0, 5, 6, |
| 8, 0, 8}, |
| n: 3, |
| uplo: blas.Upper, |
| diag: blas.NonUnit, |
| ans: []float64{ |
| 0.5, -0.3, -0.025, |
| 0, 0.2, -0.15, |
| 8, 0, 0.125, |
| }, |
| }, |
| { |
| a: []float64{ |
| 5, 3, 4, |
| 0, 7, 6, |
| 10, 0, 8}, |
| n: 3, |
| uplo: blas.Upper, |
| diag: blas.Unit, |
| ans: []float64{ |
| 5, -3, 14, |
| 0, 7, -6, |
| 10, 0, 8, |
| }, |
| }, |
| { |
| a: []float64{ |
| 2, 0, 0, |
| 3, 5, 0, |
| 4, 6, 8}, |
| n: 3, |
| uplo: blas.Lower, |
| diag: blas.NonUnit, |
| ans: []float64{ |
| 0.5, 0, 0, |
| -0.3, 0.2, 0, |
| -0.025, -0.15, 0.125, |
| }, |
| }, |
| { |
| a: []float64{ |
| 1, 0, 0, |
| 3, 1, 0, |
| 4, 6, 1}, |
| n: 3, |
| uplo: blas.Lower, |
| diag: blas.Unit, |
| ans: []float64{ |
| 1, 0, 0, |
| -3, 1, 0, |
| 14, -6, 1, |
| }, |
| }, |
| } { |
| impl.Dtrti2(test.uplo, test.diag, test.n, test.a, test.n) |
| if !floats.EqualApprox(test.ans, test.a, tol) { |
| t.Errorf("Matrix inverse mismatch. Want %v, got %v.", test.ans, test.a) |
| } |
| } |
| rnd := rand.New(rand.NewSource(1)) |
| bi := blas64.Implementation() |
| for _, uplo := range []blas.Uplo{blas.Upper, blas.Lower} { |
| for _, diag := range []blas.Diag{blas.NonUnit, blas.Unit} { |
| for _, test := range []struct { |
| n, lda int |
| }{ |
| {1, 0}, |
| {2, 0}, |
| {3, 0}, |
| {1, 5}, |
| {2, 5}, |
| {3, 5}, |
| } { |
| n := test.n |
| lda := test.lda |
| if lda == 0 { |
| lda = n |
| } |
| a := make([]float64, n*lda) |
| for i := range a { |
| a[i] = rnd.Float64() |
| } |
| aCopy := make([]float64, len(a)) |
| copy(aCopy, a) |
| impl.Dtrti2(uplo, diag, n, a, lda) |
| if uplo == blas.Upper { |
| for i := 1; i < n; i++ { |
| for j := 0; j < i; j++ { |
| aCopy[i*lda+j] = 0 |
| a[i*lda+j] = 0 |
| } |
| } |
| } else { |
| for i := 0; i < n; i++ { |
| for j := i + 1; j < n; j++ { |
| aCopy[i*lda+j] = 0 |
| a[i*lda+j] = 0 |
| } |
| } |
| } |
| if diag == blas.Unit { |
| for i := 0; i < n; i++ { |
| a[i*lda+i] = 1 |
| aCopy[i*lda+i] = 1 |
| } |
| } |
| ans := make([]float64, len(a)) |
| bi.Dgemm(blas.NoTrans, blas.NoTrans, n, n, n, 1, a, lda, aCopy, lda, 0, ans, lda) |
| iseye := true |
| for i := 0; i < n; i++ { |
| for j := 0; j < n; j++ { |
| if i == j { |
| if math.Abs(ans[i*lda+i]-1) > tol { |
| iseye = false |
| break |
| } |
| } else { |
| if math.Abs(ans[i*lda+j]) > tol { |
| iseye = false |
| break |
| } |
| } |
| } |
| } |
| if !iseye { |
| t.Errorf("inv(A) * A != I. Upper = %v, unit = %v, ans = %v", uplo == blas.Upper, diag == blas.Unit, ans) |
| } |
| } |
| } |
| } |
| } |