lapack: imported lapack as a subtree

lapack/testlapack/dlarfx.go

@@ -0,0 +1,82 @@
+// 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/blas/blas64"
+)
+
+type Dlarfxer interface {
+	Dlarfx(side blas.Side, m, n int, v []float64, tau float64, c []float64, ldc int, work []float64)
+}
+
+func DlarfxTest(t *testing.T, impl Dlarfxer) {
+	rnd := rand.New(rand.NewSource(1))
+	for _, side := range []blas.Side{blas.Right, blas.Left} {
+		for m := 1; m < 12; m++ {
+			for n := 1; n < 12; n++ {
+				for _, extra := range []int{0, 1, 11} {
+					for cas := 0; cas < 10; cas++ {
+						testDlarfx(t, impl, side, m, n, extra, rnd)
+					}
+				}
+			}
+		}
+	}
+}
+
+func testDlarfx(t *testing.T, impl Dlarfxer, side blas.Side, m, n, extra int, rnd *rand.Rand) {
+	const tol = 1e-13
+
+	c := randomGeneral(m, n, n+extra, rnd)
+	cWant := randomGeneral(m, n, n+extra, rnd)
+	tau := rnd.NormFloat64()
+
+	var (
+		v []float64
+		h blas64.General
+	)
+	if side == blas.Left {
+		v = randomSlice(m, rnd)
+		h = eye(m, m+extra)
+	} else {
+		v = randomSlice(n, rnd)
+		h = eye(n, n+extra)
+	}
+	blas64.Ger(-tau, blas64.Vector{Inc: 1, Data: v}, blas64.Vector{Inc: 1, Data: v}, h)
+	if side == blas.Left {
+		blas64.Gemm(blas.NoTrans, blas.NoTrans, 1, h, c, 0, cWant)
+	} else {
+		blas64.Gemm(blas.NoTrans, blas.NoTrans, 1, c, h, 0, cWant)
+	}
+
+	var work []float64
+	if h.Rows > 10 {
+		// Allocate work only if H has order > 10.
+		if side == blas.Left {
+			work = make([]float64, n)
+		} else {
+			work = make([]float64, m)
+		}
+	}
+
+	impl.Dlarfx(side, m, n, v, tau, c.Data, c.Stride, work)
+
+	prefix := fmt.Sprintf("Case side=%v, m=%v, n=%v, extra=%v", side, m, n, extra)
+
+	// Check any invalid modifications of c.
+	if !generalOutsideAllNaN(c) {
+		t.Errorf("%v: out-of-range write to C\n%v", prefix, c.Data)
+	}
+
+	if !equalApproxGeneral(c, cWant, tol) {
+		t.Errorf("%v: unexpected C\n%v", prefix, c.Data)
+	}
+}