Пример #1
0
func TestTriRedUpper(t *testing.T) {
	N := 843
	nb := 48
	conf := gomas.NewConf()
	conf.LB = 0

	A := cmat.NewMatrix(N, N)
	tau := cmat.NewMatrix(N, 1)
	src := cmat.NewFloatNormSource()
	A.SetFrom(src, cmat.UPPER)
	A1 := cmat.NewCopy(A)
	tau1 := cmat.NewCopy(tau)
	_ = A1

	W := lapackd.Workspace(N)
	W1 := lapackd.Workspace(N * nb)

	lapackd.TRDReduce(A, tau, W, gomas.UPPER, conf)

	conf.LB = nb
	lapackd.TRDReduce(A1, tau1, W1, gomas.UPPER, conf)

	blasd.Plus(A, A1, -1.0, 1.0, gomas.NONE)
	nrm := lapackd.NormP(A, lapackd.NORM_ONE)
	t.Logf("N=%d, ||unblk.Trired(A) - blk.Trired(A)||_1: %e\n", N, nrm)
	blasd.Axpy(tau, tau1, -1.0)
	nrm = blasd.Nrm2(tau)
	t.Logf("   ||unblk.Trired(tau) - blk.Trired(tau)||_1: %e\n", nrm)
}
Пример #2
0
// Compute eigenvector corresponding precomputed deltas
func trdsecEigenVecDelta(qi, delta, z *cmat.FloatMatrix) {
	var dk, zk float64

	for k := 0; k < delta.Len(); k++ {
		zk = z.GetAt(k)
		dk = delta.GetAt(k)
		qi.SetAt(k, zk/dk)
	}
	s := blasd.Nrm2(qi)
	blasd.InvScale(qi, s)
}
Пример #3
0
// test: unblk.QLFactor == blk.QLFactor
func TestQLFactor(t *testing.T) {
	var t0 cmat.FloatMatrix
	M := 911
	N := 835
	nb := 32
	conf := gomas.NewConf()

	A := cmat.NewMatrix(M, N)
	src := cmat.NewFloatNormSource()
	A.SetFrom(src)
	tau := cmat.NewMatrix(M, 1)
	W := cmat.NewMatrix(M+N, 1)

	A1 := cmat.NewCopy(A)
	tau1 := cmat.NewCopy(tau)

	conf.LB = 0
	lapackd.QLFactor(A, tau, W, conf)

	conf.LB = nb
	W1 := lapackd.Workspace(lapackd.QLFactorWork(A1, conf))
	lapackd.QLFactor(A1, tau1, W1, conf)

	if N < 10 {
		t.Logf("unblkQL(A):\n%v\n", A)
		t0.SetBuf(1, tau.Len(), 1, tau.Data())
		t.Logf("unblkQL.tau:\n%v\n", &t0)
		t.Logf("blkQL(A):\n%v\n", A1)
		t0.SetBuf(1, tau1.Len(), 1, tau1.Data())
		t.Logf("blkQL.tau:\n%v\n", &t0)
	}

	blasd.Plus(A1, A, 1.0, -1.0, gomas.NONE)
	nrm := lapackd.NormP(A1, lapackd.NORM_ONE)
	t.Logf("M=%d, N=%d ||blkQL(A) - unblkQL(A)||_1: %e\n", M, N, nrm)

	blasd.Axpy(tau1, tau, -1.0)
	nrm = blasd.Nrm2(tau1)
	t.Logf("     ||blkQL.tau - unblkQL.tau||_1: %e\n", nrm)

}
Пример #4
0
/*
 * Compute matrix and vector norms.
 *
 * Arguments
 *  X    A real valued matrix or vector
 *
 *  norm Norm to compute
 *         NORM_ONE, NORM_TWO, NORM_INF
 *
 * Note: matrix NORM_TWO not yet implemented.
 */
func NormP(X *cmat.FloatMatrix, norm Norms) float64 {
	if X.IsVector() {
		switch norm {
		case NORM_ONE:
			return blasd.ASum(X)
		case NORM_TWO:
			return blasd.Nrm2(X)
		case NORM_INF:
			return blasd.Amax(X)
		}
		return 0.0
	}
	switch norm {
	case NORM_ONE:
		return mNorm1(X)
	case NORM_TWO:
		return 0.0
	case NORM_INF:
		return mNormInf(X)
	}
	return 0.0
}
Пример #5
0
func trdsecEigenBuildInplace(Q, z *cmat.FloatMatrix) {
	var QTL, QBR, Q00, q11, q12, q21, Q22, qi cmat.FloatMatrix
	var zk0, zk1, dk0, dk1 float64

	util.Partition2x2(
		&QTL, nil,
		nil, &QBR /**/, Q, 0, 0, util.PTOPLEFT)

	for m(&QBR) > 0 {
		util.Repartition2x2to3x3(&QTL,
			&Q00, nil, nil,
			nil, &q11, &q12,
			nil, &q21, &Q22 /**/, Q, 1, util.PBOTTOMRIGHT)
		//---------------------------------------------------------------
		k := m(&Q00)
		zk0 = z.GetAt(k)
		dk0 = q11.Get(0, 0)
		q11.Set(0, 0, zk0/dk0)

		for i := 0; i < q12.Len(); i++ {
			zk1 = z.GetAt(k + i + 1)
			dk0 = q12.GetAt(i)
			dk1 = q21.GetAt(i)
			q12.SetAt(i, zk0/dk1)
			q21.SetAt(i, zk1/dk0)
		}
		//---------------------------------------------------------------
		util.Continue3x3to2x2(
			&QTL, nil,
			nil, &QBR /**/, &Q00, &q11, &Q22 /**/, Q, util.PBOTTOMRIGHT)
	}
	// scale column eigenvectors
	for k := 0; k < z.Len(); k++ {
		qi.Column(Q, k)
		t := blasd.Nrm2(&qi)
		blasd.InvScale(&qi, t)
	}
}
Пример #6
0
func test1(N int, beta float64, t *testing.T) {
	var sI cmat.FloatMatrix

	if N&0x1 != 0 {
		N = N + 1
	}
	D := cmat.NewMatrix(N, 1)
	Z := cmat.NewMatrix(N, 1)
	Y := cmat.NewMatrix(N, 1)
	V := cmat.NewMatrix(N, 1)
	Q := cmat.NewMatrix(N, N)
	I := cmat.NewMatrix(N, N)

	D.SetAt(0, 1.0)
	Z.SetAt(0, 2.0)
	for i := 1; i < N-1; i++ {
		if i < N/2 {
			D.SetAt(i, 2.0-float64(N/2-i)*beta)
		} else {
			D.SetAt(i, 2.0+float64(i+1-N/2)*beta)
		}
		Z.SetAt(i, beta)
	}
	D.SetAt(N-1, 10.0/3.0)
	Z.SetAt(N-1, 2.0)
	w := blasd.Nrm2(Z)
	blasd.InvScale(Z, w)
	rho := 1.0 / (w * w)

	lapackd.TRDSecularSolveAll(Y, V, Q, D, Z, rho)
	lapackd.TRDSecularEigen(Q, V, nil)
	blasd.Mult(I, Q, Q, 1.0, 0.0, gomas.TRANSA)
	sI.Diag(I)
	sI.Add(-1.0)
	nrm := lapackd.NormP(I, lapackd.NORM_ONE)
	t.Logf("N=%d, beta=%e ||I - Q.T*Q||_1: %e\n", N, beta, nrm)
}
Пример #7
0
/* From LAPACK/dlarfg.f
 *
 * Generates a real elementary reflector H of order n, such
 * that
 *
 *       H * ( alpha ) = ( beta ),   H**T * H = I.
 *           (   x   )   (   0  )
 *
 * where alpha and beta are scalars, and x is an (n-1)-element real
 * vector. H is represented in the form
 *
 *       H = I - tau * ( 1 ) * ( 1 v**T ) ,
 *                     ( v )
 *
 * where tau is a real scalar and v is a real (n-1)-element
 * vector.
 *
 * If the elements of x are all zero, then tau = 0 and H is taken to be
 * the unit cmat.
 *
 * Otherwise  1 <= tau <= 2.
 */
func computeHouseholder(a11, x, tau *cmat.FloatMatrix) {

	// norm_x2 = ||x||_2
	norm_x2 := blasd.Nrm2(x)
	if norm_x2 == 0.0 {
		tau.Set(0, 0, 0.0)
		return
	}

	alpha := a11.Get(0, 0)
	sign := 1.0
	if math.Signbit(alpha) {
		sign = -1.0
	}
	// beta = -(alpha / |alpha|) * ||alpha x||
	//      = -sign(alpha) * sqrt(alpha**2, norm_x2**2)
	beta := -sign * sqrtX2Y2(alpha, norm_x2)

	// x = x /(a11 - beta)
	blasd.InvScale(x, alpha-beta)

	tau.Set(0, 0, (beta-alpha)/beta)
	a11.Set(0, 0, beta)
}