lapack: imported lapack as a subtree

lapack/testlapack/dlasr.go

@@ -0,0 +1,148 @@
+// 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"
+
+	"github.com/gonum/blas"
+	"github.com/gonum/blas/blas64"
+	"github.com/gonum/floats"
+	"github.com/gonum/lapack"
+)
+
+type Dlasrer interface {
+	Dlasr(side blas.Side, pivot lapack.Pivot, direct lapack.Direct, m, n int, c, s, a []float64, lda int)
+}
+
+func DlasrTest(t *testing.T, impl Dlasrer) {
+	rnd := rand.New(rand.NewSource(1))
+	for _, side := range []blas.Side{blas.Left, blas.Right} {
+		for _, pivot := range []lapack.Pivot{lapack.Variable, lapack.Top, lapack.Bottom} {
+			for _, direct := range []lapack.Direct{lapack.Forward, lapack.Backward} {
+				for _, test := range []struct {
+					m, n, lda int
+				}{
+					{5, 5, 0},
+					{5, 10, 0},
+					{10, 5, 0},
+
+					{5, 5, 20},
+					{5, 10, 20},
+					{10, 5, 20},
+				} {
+					m := test.m
+					n := test.n
+					lda := test.lda
+					if lda == 0 {
+						lda = n
+					}
+					a := make([]float64, m*lda)
+					for i := range a {
+						a[i] = rnd.Float64()
+					}
+					var s, c []float64
+					if side == blas.Left {
+						s = make([]float64, m-1)
+						c = make([]float64, m-1)
+					} else {
+						s = make([]float64, n-1)
+						c = make([]float64, n-1)
+					}
+					for k := range s {
+						theta := rnd.Float64() * 2 * math.Pi
+						s[k] = math.Sin(theta)
+						c[k] = math.Cos(theta)
+					}
+					aCopy := make([]float64, len(a))
+					copy(a, aCopy)
+					impl.Dlasr(side, pivot, direct, m, n, c, s, a, lda)
+
+					pSize := m
+					if side == blas.Right {
+						pSize = n
+					}
+					p := blas64.General{
+						Rows:   pSize,
+						Cols:   pSize,
+						Stride: pSize,
+						Data:   make([]float64, pSize*pSize),
+					}
+					pk := blas64.General{
+						Rows:   pSize,
+						Cols:   pSize,
+						Stride: pSize,
+						Data:   make([]float64, pSize*pSize),
+					}
+					ptmp := blas64.General{
+						Rows:   pSize,
+						Cols:   pSize,
+						Stride: pSize,
+						Data:   make([]float64, pSize*pSize),
+					}
+					for i := 0; i < pSize; i++ {
+						p.Data[i*p.Stride+i] = 1
+						ptmp.Data[i*p.Stride+i] = 1
+					}
+					// Compare to direct computation.
+					for k := range s {
+						for i := range p.Data {
+							pk.Data[i] = 0
+						}
+						for i := 0; i < pSize; i++ {
+							pk.Data[i*p.Stride+i] = 1
+						}
+						if pivot == lapack.Variable {
+							pk.Data[k*p.Stride+k] = c[k]
+							pk.Data[k*p.Stride+k+1] = s[k]
+							pk.Data[(k+1)*p.Stride+k] = -s[k]
+							pk.Data[(k+1)*p.Stride+k+1] = c[k]
+						} else if pivot == lapack.Top {
+							pk.Data[0] = c[k]
+							pk.Data[k+1] = s[k]
+							pk.Data[(k+1)*p.Stride] = -s[k]
+							pk.Data[(k+1)*p.Stride+k+1] = c[k]
+						} else {
+							pk.Data[(pSize-1-k)*p.Stride+pSize-k-1] = c[k]
+							pk.Data[(pSize-1-k)*p.Stride+pSize-1] = s[k]
+							pk.Data[(pSize-1)*p.Stride+pSize-1-k] = -s[k]
+							pk.Data[(pSize-1)*p.Stride+pSize-1] = c[k]
+						}
+						if direct == lapack.Forward {
+							blas64.Gemm(blas.NoTrans, blas.NoTrans, 1, pk, ptmp, 0, p)
+						} else {
+							blas64.Gemm(blas.NoTrans, blas.NoTrans, 1, ptmp, pk, 0, p)
+						}
+						copy(ptmp.Data, p.Data)
+					}
+
+					aMat := blas64.General{
+						Rows:   m,
+						Cols:   n,
+						Stride: lda,
+						Data:   make([]float64, m*lda),
+					}
+					copy(a, aCopy)
+					newA := blas64.General{
+						Rows:   m,
+						Cols:   n,
+						Stride: lda,
+						Data:   make([]float64, m*lda),
+					}
+					if side == blas.Left {
+						blas64.Gemm(blas.NoTrans, blas.NoTrans, 1, p, aMat, 0, newA)
+					} else {
+						blas64.Gemm(blas.NoTrans, blas.NoTrans, 1, aMat, p, 0, newA)
+					}
+					if !floats.EqualApprox(newA.Data, a, 1e-12) {
+						t.Errorf("A update mismatch")
+					}
+				}
+			}
+		}
+	}
+}