/*
* Build full block reflect T for nc columns from sequence of reflector stored in S.
* Reflectors in S are the diagonal of T, off-diagonal values of reflector are computed
* from elementary reflector store in lower triangular part of A.
*/
func buildQRTReflector(T, A, S *cmat.FloatMatrix, nc int, conf *gomas.Config) *gomas.Error {
var ATL, ATR, ABL, ABR cmat.FloatMatrix
var A00, A10, A11, A20, A21, A22 cmat.FloatMatrix
var TTL, TTR, TBL, TBR cmat.FloatMatrix
var T00, T01, T02, T11, T12, T22 cmat.FloatMatrix
var SL, SR cmat.FloatMatrix
var S00, S01, S02 cmat.FloatMatrix
util.Partition2x2(
&ATL, &ATR,
&ABL, &ABR, A, 0, 0, util.PTOPLEFT)
util.Partition2x2(
&TTL, &TTR,
&TBL, &TBR, T, 0, 0, util.PTOPLEFT)
util.Partition1x2(
&SL, &SR, S, 0, util.PLEFT)
nb := conf.LB
for m(&ABR)-nb > 0 && n(&ABR)-nb > 0 {
util.Repartition2x2to3x3(&ATL,
&A00, nil, nil,
&A10, &A11, nil,
&A20, &A21, &A22, A, nb, util.PBOTTOMRIGHT)
util.Repartition2x2to3x3(&TTL,
&T00, &T01, &T02,
nil, &T11, &T12,
nil, nil, &T22, T, nb, util.PBOTTOMRIGHT)
util.Repartition1x2to1x3(&SL,
&S00, &S01, &S02, S, nb, util.PRIGHT)
// --------------------------------------------------------
// update T01: T01 = -T00*Y1.T*Y2*T11
// Y1 = /A10\ Y2 = /A11\
// \A20/ \A21/
//
T11.Copy(&S01)
updateQRTReflector(&T01, &A10, &A20, &A11, &A21, &T00, &S01, conf)
// --------------------------------------------------------
util.Continue3x3to2x2(
&ATL, &ATR,
&ABL, &ABR, &A00, &A11, &A22, A, util.PBOTTOMRIGHT)
util.Continue3x3to2x2(
&TTL, &TTR,
&TBL, &TBR, &T00, &T11, &T22, T, util.PBOTTOMRIGHT)
util.Continue1x3to1x2(
&SL, &SR, &S00, &S01, S, util.PRIGHT)
}
if m(&ABR) > 0 && n(&ABR) > 0 {
}
return nil
}
func testEigen(N int, bits int, t *testing.T) {
var A, A0, W, D, V *cmat.FloatMatrix
var sD cmat.FloatMatrix
var s string = "lower"
if bits&gomas.UPPER != 0 {
s = "upper"
}
wsize := N * N
if wsize < 100 {
wsize = 100
}
D = cmat.NewMatrix(N, 1)
A = cmat.NewMatrix(N, N)
V = cmat.NewMatrix(N, N)
src := cmat.NewFloatNormSource()
A.SetFrom(src, cmat.SYMM)
A0 = cmat.NewCopy(A)
W = cmat.NewMatrix(wsize, 1)
if err := lapackd.EigenSym(D, A, W, bits|gomas.WANTV); err != nil {
t.Errorf("EigenSym error: %v\n", err)
return
}
// ||I - V.T*V||
sD.Diag(V)
blasd.Mult(V, A, A, 1.0, 0.0, gomas.TRANSA)
blasd.Add(&sD, -1.0)
nrm1 := lapackd.NormP(V, lapackd.NORM_ONE)
// left vectors are M-by-N
V.Copy(A)
lapackd.MultDiag(V, D, gomas.RIGHT)
blasd.Mult(A0, V, A, -1.0, 1.0, gomas.TRANSB)
nrm2 := lapackd.NormP(A0, lapackd.NORM_ONE)
t.Logf("N=%d, [%s] ||A - V*D*V.T||_1 :%e\n", N, s, nrm2)
t.Logf(" ||I - V.T*V||_1 : %e\n", nrm1)
}
func TestSubMatrixCopy(t *testing.T) {
var subA, subB cmat.FloatMatrix
M := 9
N := 9
A := cmat.NewMatrix(M, N)
B := cmat.NewMatrix(M, N)
twos := cmat.NewFloatConstSource(2.0)
B.SetFrom(twos)
subA.SubMatrix(A, 1, 1, M-2, N-2)
subB.SubMatrix(B, 1, 1, M-2, N-2)
subA.Copy(&subB)
ok := subA.AllClose(&subB)
if !ok {
t.Logf("copy status: %v\n", ok)
if N < 9 {
t.Logf("subA\n%v\n", subA)
}
}
if N < 10 {
t.Logf("A\n%v\n", A)
}
}
/*
* Find diagonal pivot and build incrementaly updated block.
*
* (AL) (AR) (WL) (WR)
* -------------------------- ---------- k'th row in W
* x x | c1 w w | k kp1
* x x | c1 d w w | k kp1
* x x | c1 x d w w | k kp1
* x x | c1 x x d w w | k kp1
* x x | c1 r2 r2 r2 r2 w w | k kp1
* x x | c1 x x x r2 d w w | k kp1
* x x | c1 x x x r2 x d w w | k kp1
*
* Matrix AR contains the unfactored part of the matrix and AL the already
* factored columns. Matrix WL is updated values of factored part ie.
* w(i) = l(i)d(i). Matrix WR will have updated values for next column.
* Column WR(k) contains updated AR(c1) and WR(kp1) possible pivot row AR(r2).
*/
func findAndBuildBKPivotLower(AL, AR, WL, WR *cmat.FloatMatrix, k int) (int, int) {
var r, q int
var rcol, qrow, src, wk, wkp1, wrow cmat.FloatMatrix
// Copy AR column 0 to WR column 0 and update with WL[0:]
src.SubMatrix(AR, 0, 0, m(AR), 1)
wk.SubMatrix(WR, 0, 0, m(AR), 1)
wk.Copy(&src)
if k > 0 {
wrow.SubMatrix(WL, 0, 0, 1, n(WL))
blasd.MVMult(&wk, AL, &wrow, -1.0, 1.0, gomas.NONE)
}
if m(AR) == 1 {
return 0, 1
}
amax := math.Abs(WR.Get(0, 0))
// find max off-diagonal on first column.
rcol.SubMatrix(WR, 1, 0, m(AR)-1, 1)
// r is row index and rmax is its absolute value
r = blasd.IAmax(&rcol) + 1
rmax := math.Abs(rcol.Get(r-1, 0))
if amax >= bkALPHA*rmax {
// no pivoting, 1x1 diagonal
return 0, 1
}
// Now we need to copy row r to WR[:,1] and update it
wkp1.SubMatrix(WR, 0, 1, m(AR), 1)
qrow.SubMatrix(AR, r, 0, 1, r+1)
blasd.Copy(&wkp1, &qrow)
if r < m(AR)-1 {
var wkr cmat.FloatMatrix
qrow.SubMatrix(AR, r, r, m(AR)-r, 1)
wkr.SubMatrix(&wkp1, r, 0, m(&wkp1)-r, 1)
blasd.Copy(&wkr, &qrow)
}
if k > 0 {
// update wkp1
wrow.SubMatrix(WL, r, 0, 1, n(WL))
blasd.MVMult(&wkp1, AL, &wrow, -1.0, 1.0, gomas.NONE)
}
// set on-diagonal entry to zero to avoid finding it
p1 := wkp1.Get(r, 0)
wkp1.Set(r, 0, 0.0)
// max off-diagonal on r'th column/row at index q
q = blasd.IAmax(&wkp1)
qmax := math.Abs(wkp1.Get(q, 0))
// restore on-diagonal entry
wkp1.Set(r, 0, p1)
if amax >= bkALPHA*rmax*(rmax/qmax) {
// no pivoting, 1x1 diagonal
return 0, 1
}
// if q == r then qmax is not off-diagonal, qmax == WR[r,1] and
// we get 1x1 pivot as following is always true
if math.Abs(WR.Get(r, 1)) >= bkALPHA*qmax {
// 1x1 pivoting and interchange with k, r
// pivot row in column WR[:,1] to W[:,0]
src.SubMatrix(WR, 0, 1, m(AR), 1)
wkp1.SubMatrix(WR, 0, 0, m(AR), 1)
blasd.Copy(&wkp1, &src)
wkp1.Set(0, 0, src.Get(r, 0))
wkp1.Set(r, 0, src.Get(0, 0))
return r, 1
} else {
// 2x2 pivoting and interchange with k+1, r
return r, 2
}
return 0, 1
}
func svdWide(S, U, V, A, W *cmat.FloatMatrix, bits int, conf *gomas.Config) (err *gomas.Error) {
var uu, vv *cmat.FloatMatrix
var tauq, taup, Wred, sD, sE, L, Vm cmat.FloatMatrix
if (bits & (gomas.WANTU | gomas.WANTV)) != 0 {
if W.Len() < 4*n(A) {
err = gomas.NewError(gomas.ESIZE, "SVD")
return
}
}
tauq.SetBuf(m(A)-1, 1, m(A)-1, W.Data())
taup.SetBuf(m(A), 1, m(A), W.Data()[tauq.Len():])
wrl := W.Len() - 2*m(A) - 1
Wred.SetBuf(wrl, 1, wrl, W.Data()[2*m(A)-1:])
if svdCrossover(n(A), m(A)) {
goto do_n_much_bigger
}
// reduce to bidiagonal form
if err = BDReduce(A, &tauq, &taup, &Wred, conf); err != nil {
return
}
sD.Diag(A)
sE.Diag(A, -1)
blasd.Copy(S, &sD)
// leftt vectors
if bits&gomas.WANTU != 0 {
L.SubMatrix(A, 0, 0, m(A), m(A))
U.Copy(&L)
cmat.TriL(U, 0)
if err = BDBuild(U, &tauq, &Wred, m(U), gomas.WANTQ|gomas.LOWER, conf); err != nil {
return
}
uu = U
}
// right vectors
if bits&gomas.WANTV != 0 {
if m(V) == m(A) {
// V is M-by-N; copy and make upper triangular
V.Copy(A)
//cmat.TriU(V, 0)
if err = BDBuild(V, &taup, &Wred, m(V), gomas.WANTP, conf); err != nil {
return
}
} else {
// V is N-by-N
eye := cmat.FloatDiagonalSource{1.0}
V.SetFrom(&eye, cmat.SYMM)
err = BDMult(V, A, &taup, &Wred, gomas.MULTP|gomas.LEFT|gomas.TRANS, conf)
if err != nil {
return
}
}
vv = V
}
err = BDSvd(S, &sE, uu, vv, W, bits|gomas.LOWER)
return
do_n_much_bigger:
// here N >> M, use LQ factor first
if err = LQFactor(A, &taup, &Wred, conf); err != nil {
return
}
if bits&gomas.WANTV != 0 {
if m(V) == m(A) {
V.Copy(A)
if err = LQBuild(V, &taup, &Wred, m(A), conf); err != nil {
return
}
} else {
// V is N-by-N
eye := cmat.FloatDiagonalSource{1.0}
V.SetFrom(&eye, cmat.SYMM)
if err = LQMult(V, A, &taup, &Wred, gomas.RIGHT, conf); err != nil {
return
}
}
}
L.SubMatrix(A, 0, 0, m(A), m(A))
cmat.TriL(&L, 0)
// resize tauq/taup for UPPER bidiagonal reduction
tauq.SetBuf(m(A), 1, m(A), W.Data())
taup.SetBuf(m(A)-1, 1, m(A)-1, W.Data()[tauq.Len():])
// bidiagonal reduce
if err = BDReduce(&L, &tauq, &taup, &Wred, conf); err != nil {
return
}
if bits&gomas.WANTV != 0 {
Vm.SubMatrix(V, 0, 0, m(A), n(A))
err = BDMult(&Vm, &L, &taup, &Wred, gomas.MULTP|gomas.LEFT|gomas.TRANS, conf)
if err != nil {
return
}
vv = V
}
if bits&gomas.WANTU != 0 {
U.Copy(&L)
if err = BDBuild(U, &tauq, &Wred, m(U), gomas.WANTQ, conf); err != nil {
return
}
uu = U
}
sD.Diag(A)
sE.Diag(A, 1)
blasd.Copy(S, &sD)
err = BDSvd(S, &sE, uu, vv, W, bits|gomas.UPPER, conf)
return
}
func svdSmall(S, U, V, A, W *cmat.FloatMatrix, bits int, conf *gomas.Config) (err *gomas.Error) {
var r cmat.FloatMatrix
var d0, d1, e0 float64
err = nil
K := m(A)
if n(A) < K {
K = n(A)
}
tau := cmat.NewMatrix(K, 1)
if m(A) >= n(A) {
if err = QRFactor(A, tau, W, conf); err != nil {
return
}
} else {
if err = LQFactor(A, tau, W, conf); err != nil {
return
}
}
if m(A) == 1 || n(A) == 1 {
// either tall M-by-1 or wide 1-by-N
S.SetAt(0, math.Abs(A.Get(0, 0)))
if bits&gomas.WANTU != 0 {
if n(A) == 1 {
if n(U) == n(A) {
// U is M-by-1
U.Copy(A)
QRBuild(U, tau, W, n(A), conf)
} else {
// U is M-by-M
eye := cmat.FloatDiagonalSource{1.0}
U.SetFrom(&eye, cmat.SYMM)
if err = QRMult(U, A, tau, W, gomas.RIGHT, conf); err != nil {
return
}
}
} else {
U.Set(0, 0, -1.0)
}
}
if bits&gomas.WANTV != 0 {
if m(A) == 1 {
if m(V) == m(A) {
// V is 1-by-N
V.Copy(A)
LQBuild(V, tau, W, m(A), conf)
} else {
// V is N-by-N
eye := cmat.FloatDiagonalSource{1.0}
V.SetFrom(&eye, cmat.SYMM)
if err = LQMult(V, A, tau, W, gomas.RIGHT, conf); err != nil {
return
}
}
} else {
// V is 1-by-1
V.Set(0, 0, -1.0)
}
}
return
}
// Use bdSvd2x2 functions
d0 = A.Get(0, 0)
d1 = A.Get(1, 1)
if m(A) >= n(A) {
e0 = A.Get(0, 1)
} else {
e0 = A.Get(1, 0)
}
if bits&(gomas.WANTU|gomas.WANTV) == 0 {
// no vectors
smin, smax := bdSvd2x2(d0, e0, d1)
S.SetAt(0, math.Abs(smax))
S.SetAt(1, math.Abs(smin))
return
}
// at least left or right eigenvector wanted
smin, smax, cosl, sinl, cosr, sinr := bdSvd2x2Vec(d0, e0, d1)
if bits&gomas.WANTU != 0 {
// left eigenvectors
if m(A) >= n(A) {
if n(U) == n(A) {
U.Copy(A)
if err = QRBuild(U, tau, W, n(A), conf); err != nil {
return
}
} else {
// U is M-by-M
eye := cmat.FloatDiagonalSource{1.0}
U.SetFrom(&eye, cmat.SYMM)
if err = QRMult(U, A, tau, W, gomas.RIGHT, conf); err != nil {
return
}
}
ApplyGivensRight(U, 0, 1, 0, m(A), cosl, sinl)
} else {
// U is 2-by-2
eye := cmat.FloatDiagonalSource{1.0}
U.SetFrom(&eye, cmat.SYMM)
ApplyGivensRight(U, 0, 1, 0, m(A), cosr, sinr)
}
}
if bits&gomas.WANTV != 0 {
if n(A) > m(A) {
if m(V) == m(A) {
V.Copy(A)
if err = LQBuild(V, tau, W, m(A), conf); err != nil {
return
}
} else {
eye := cmat.FloatDiagonalSource{1.0}
V.SetFrom(&eye, cmat.SYMM)
if err = LQMult(V, A, tau, W, gomas.RIGHT, conf); err != nil {
return
}
}
ApplyGivensLeft(V, 0, 1, 0, n(A), cosl, sinl)
} else {
// V is 2-by-2
eye := cmat.FloatDiagonalSource{1.0}
V.SetFrom(&eye, cmat.SYMM)
ApplyGivensLeft(V, 0, 1, 0, n(A), cosr, sinr)
}
if smax < 0.0 {
r.Row(V, 0)
blasd.Scale(&r, -1.0)
}
if smin < 0.0 {
r.Row(V, 1)
blasd.Scale(&r, -1.0)
}
}
S.SetAt(0, math.Abs(smax))
S.SetAt(1, math.Abs(smin))
return
}
// Compute SVD when m(A) >= n(A)
func svdTall(S, U, V, A, W *cmat.FloatMatrix, bits int, conf *gomas.Config) (err *gomas.Error) {
var uu, vv *cmat.FloatMatrix
var tauq, taup, Wred, sD, sE, R, Un cmat.FloatMatrix
if (bits & (gomas.WANTU | gomas.WANTV)) != 0 {
if W.Len() < 4*n(A) {
err = gomas.NewError(gomas.ESIZE, "SVD")
return
}
}
tauq.SetBuf(n(A), 1, n(A), W.Data())
taup.SetBuf(n(A)-1, 1, n(A)-1, W.Data()[tauq.Len():])
wrl := W.Len() - 2*n(A) - 1
Wred.SetBuf(wrl, 1, wrl, W.Data()[2*n(A)-1:])
if svdCrossover(m(A), n(A)) {
goto do_m_much_bigger
}
// reduce to bidiagonal form
if err = BDReduce(A, &tauq, &taup, &Wred, conf); err != nil {
return
}
sD.Diag(A)
sE.Diag(A, 1)
blasd.Copy(S, &sD)
// left vectors
if bits&gomas.WANTU != 0 {
if n(U) == n(A) {
// U is M-by-N; copy and make lower triangular
U.Copy(A)
cmat.TriL(U, 0)
if err = BDBuild(U, &tauq, &Wred, n(U), gomas.WANTQ, conf); err != nil {
return
}
} else {
// U is M-by-M
eye := cmat.FloatDiagonalSource{1.0}
U.SetFrom(&eye, cmat.SYMM)
if err = BDMult(U, A, &tauq, &Wred, gomas.MULTQ|gomas.RIGHT, conf); err != nil {
return
}
}
uu = U
}
// right vectors
if bits&gomas.WANTV != 0 {
R.SubMatrix(A, 0, 0, n(A), n(A))
V.Copy(&R)
cmat.TriU(V, 0)
if err = BDBuild(V, &taup, &Wred, m(V), gomas.WANTP, conf); err != nil {
return
}
vv = V
}
err = BDSvd(S, &sE, uu, vv, W, bits|gomas.UPPER)
return
do_m_much_bigger:
// M >> N here; first use QR factorization
if err = QRFactor(A, &tauq, &Wred, conf); err != nil {
return
}
if bits&gomas.WANTU != 0 {
if n(U) == n(A) {
U.Copy(A)
if err = QRBuild(U, &tauq, &Wred, n(U), conf); err != nil {
return
}
} else {
// U is M-by-M
eye := cmat.FloatDiagonalSource{1.0}
U.SetFrom(&eye, cmat.SYMM)
if err = QRMult(U, A, &tauq, &Wred, gomas.LEFT, conf); err != nil {
return
}
}
}
R.SubMatrix(A, 0, 0, n(A), n(A))
cmat.TriU(&R, 0)
// bidiagonal reduce
if err = BDReduce(&R, &tauq, &taup, &Wred, conf); err != nil {
return
}
if bits&gomas.WANTU != 0 {
Un.SubMatrix(U, 0, 0, m(A), n(A))
if err = BDMult(&Un, &R, &tauq, &Wred, gomas.MULTQ|gomas.RIGHT, conf); err != nil {
return
}
uu = U
}
if bits&gomas.WANTV != 0 {
V.Copy(&R)
if err = BDBuild(V, &taup, &Wred, m(V), gomas.WANTP, conf); err != nil {
return
}
vv = V
}
sD.Diag(A)
sE.Diag(A, 1)
blasd.Copy(S, &sD)
err = BDSvd(S, &sE, uu, vv, W, bits|gomas.UPPER, conf)
return
}
