Add Dsytrd and tests

testlapack/dsytrd.go

@@ -0,0 +1,80 @@
+// Copyright ©2016 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/rand"
+	"testing"
+
+	"github.com/gonum/blas"
+	"github.com/gonum/floats"
+)
+
+type Dsytrder interface {
+	Dsytrd(uplo blas.Uplo, n int, a []float64, lda int, d, e, tau, work []float64, lwork int)
+	Dsytd2er
+}
+
+func DsytrdTest(t *testing.T, impl Dsytrder) {
+	for _, uplo := range []blas.Uplo{blas.Upper} {
+		for _, test := range []struct {
+			n, lda int
+		}{
+			{10, 0},
+			{50, 0},
+			{100, 0},
+			{150, 0},
+			{300, 0},
+
+			{10, 20},
+			{50, 70},
+			{100, 120},
+			{150, 170},
+			{300, 320},
+		} {
+			n := test.n
+			lda := test.lda
+			if lda == 0 {
+				lda = n
+			}
+			a := make([]float64, n*lda)
+			for i := range a {
+				a[i] = rand.NormFloat64()
+			}
+			d2 := make([]float64, n)
+			e2 := make([]float64, n)
+			tau2 := make([]float64, n)
+
+			aCopy := make([]float64, len(a))
+			copy(aCopy, a)
+			impl.Dsytd2(uplo, n, a, lda, d2, e2, tau2)
+			aAns := make([]float64, len(a))
+			copy(aAns, a)
+
+			copy(a, aCopy)
+			d := make([]float64, n)
+			e := make([]float64, n)
+			tau := make([]float64, n)
+			work := make([]float64, 1)
+			impl.Dsytrd(uplo, n, a, lda, d, e, tau, work, -1)
+			work = make([]float64, int(work[0]))
+			impl.Dsytrd(uplo, n, a, lda, d, e, tau, work, len(work))
+			errStr := fmt.Sprintf("upper = %v, n = %v", uplo == blas.Upper, n)
+			if !floats.EqualApprox(a, aAns, 1e-8) {
+				t.Errorf("A mismatch: %s", errStr)
+			}
+			if !floats.EqualApprox(d, d2, 1e-8) {
+				t.Errorf("D mismatch: %s", errStr)
+			}
+			if !floats.EqualApprox(e, e2, 1e-8) {
+				t.Errorf("E mismatch: %s", errStr)
+			}
+			if !floats.EqualApprox(tau, tau2, 1e-8) {
+				t.Errorf("Tau mismatch: %s", errStr)
+			}
+		}
+	}
+}