testlapack: add test for Dlascl

Closes #211

cgo/lapack_test.go

@@ -48,6 +48,10 @@ func TestDlacn2(t *testing.T) {
 	testlapack.Dlacn2Test(t, impl)
 }
 
+func TestDlascl(t *testing.T) {
+	testlapack.DlasclTest(t, impl)
+}
+
 func TestDlacpy(t *testing.T) {
 	testlapack.DlacpyTest(t, impl)
 }

native/lapack_test.go

@@ -140,6 +140,10 @@ func TestDlas2(t *testing.T) {
 	testlapack.Dlas2Test(t, impl)
 }
 
+func TestDlascl(t *testing.T) {
+	testlapack.DlasclTest(t, impl)
+}
+
 func TestDlaset(t *testing.T) {
 	testlapack.DlasetTest(t, impl)
 }

testlapack/dlascl.go

@@ -0,0 +1,106 @@
+// 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"
+	"math/rand"
+	"testing"
+
+	"github.com/gonum/lapack"
+)
+
+type Dlascler interface {
+	Dlascl(kind lapack.MatrixType, kl, ku int, cfrom, cto float64, m, n int, a []float64, lda int)
+}
+
+func DlasclTest(t *testing.T, impl Dlascler) {
+	const tol = 1e-16
+
+	rnd := rand.New(rand.NewSource(1))
+	for ti, test := range []struct {
+		m, n int
+	}{
+		{0, 0},
+		{1, 1},
+		{1, 10},
+		{10, 1},
+		{2, 2},
+		{2, 11},
+		{11, 2},
+		{3, 3},
+		{3, 11},
+		{11, 3},
+		{11, 11},
+		{11, 100},
+		{100, 11},
+	} {
+		m := test.m
+		n := test.n
+		for _, extra := range []int{0, 11} {
+			for _, kind := range []lapack.MatrixType{lapack.General, lapack.UpperTri, lapack.LowerTri} {
+				a := randomGeneral(m, n, n+extra, rnd)
+				aCopy := cloneGeneral(a)
+				cfrom := rnd.NormFloat64()
+				cto := rnd.NormFloat64()
+				scale := cto / cfrom
+
+				impl.Dlascl(kind, -1, -1, cfrom, cto, m, n, a.Data, a.Stride)
+
+				prefix := fmt.Sprintf("Case #%v: kind=%v,m=%v,n=%v,extra=%v", ti, kind, m, n, extra)
+				if !generalOutsideAllNaN(a) {
+					t.Errorf("%v: out-of-range write to A", prefix)
+				}
+				switch kind {
+				case lapack.General:
+					for i := 0; i < m; i++ {
+						for j := 0; j < n; j++ {
+							want := scale * aCopy.Data[i*aCopy.Stride+j]
+							got := a.Data[i*a.Stride+j]
+							if math.Abs(want-got) > tol {
+								t.Errorf("%v: unexpected A[%v,%v]=%v, want %v", prefix, i, j, got, want)
+							}
+						}
+					}
+				case lapack.UpperTri:
+					for i := 0; i < m; i++ {
+						for j := i; j < n; j++ {
+							want := scale * aCopy.Data[i*aCopy.Stride+j]
+							got := a.Data[i*a.Stride+j]
+							if math.Abs(want-got) > tol {
+								t.Errorf("%v: unexpected A[%v,%v]=%v, want %v", prefix, i, j, got, want)
+							}
+						}
+					}
+					for i := 0; i < m; i++ {
+						for j := 0; j < min(i, n); j++ {
+							if a.Data[i*a.Stride+j] != aCopy.Data[i*aCopy.Stride+j] {
+								t.Errorf("%v: unexpected modification in lower triangle of A", prefix)
+							}
+						}
+					}
+				case lapack.LowerTri:
+					for i := 0; i < m; i++ {
+						for j := 0; j <= min(i, n-1); j++ {
+							want := scale * aCopy.Data[i*aCopy.Stride+j]
+							got := a.Data[i*a.Stride+j]
+							if math.Abs(want-got) > tol {
+								t.Errorf("%v: unexpected A[%v,%v]=%v, want %v", prefix, i, j, got, want)
+							}
+						}
+					}
+					for i := 0; i < m; i++ {
+						for j := i + 1; j < n; j++ {
+							if a.Data[i*a.Stride+j] != aCopy.Data[i*aCopy.Stride+j] {
+								t.Errorf("%v: unexpected modification in upper triangle of A", prefix)
+							}
+						}
+					}
+				}
+			}
+		}
+	}
+}