lapack: imported lapack as a subtree

lapack/testlapack/dgebd2.go

@@ -0,0 +1,54 @@
+// 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/rand"
+	"testing"
+)
+
+type Dgebd2er interface {
+	Dgebd2(m, n int, a []float64, lda int, d, e, tauq, taup, work []float64)
+}
+
+func Dgebd2Test(t *testing.T, impl Dgebd2er) {
+	rnd := rand.New(rand.NewSource(1))
+	for _, test := range []struct {
+		m, n, lda int
+	}{
+		{3, 4, 0},
+		{4, 3, 0},
+		{3, 4, 10},
+		{4, 3, 10},
+	} {
+		m := test.m
+		n := test.n
+		lda := test.lda
+		if lda == 0 {
+			lda = n
+		}
+		nb := min(m, n) // 'nb' name parallel with Dlabrd code.
+		a := make([]float64, m*lda)
+		for i := range a {
+			a[i] = rnd.NormFloat64()
+		}
+		d := nanSlice(nb)
+		e := nanSlice(nb - 1)
+		tauP := nanSlice(nb)
+		tauQ := nanSlice(nb)
+		work := nanSlice(max(m, n))
+		aCopy := make([]float64, len(a))
+		copy(aCopy, a)
+		impl.Dgebd2(m, n, a, lda, d, e, tauQ, tauP, work)
+		if m >= n && nb == n {
+			tauP[n-1] = 0
+		}
+		if m < n && nb == m {
+			tauQ[m-1] = 0
+		}
+
+		checkBidiagonal(t, m, n, nb, a, lda, d, e, tauP, tauQ, aCopy)
+	}
+}