laeda#

Functions

void slaeda(
    const INT  n,
    const INT  tlvls,
    const INT  curlvl,
    const INT  curpbm,
          INT* prmptr,
          INT* perm,
          INT* givptr,
          INT* givcol,
          f32* givnum,
          f32* Q,
          INT* qptr,
          f32* Z,
          f32* ztemp,
          INT* info
);
void slaeda(const INT n, const INT tlvls, const INT curlvl, const INT curpbm, INT *prmptr, INT *perm, INT *givptr, INT *givcol, f32 *givnum, f32 *Q, INT *qptr, f32 *Z, f32 *ztemp, INT *info)#

SLAEDA computes the Z vector corresponding to the merge step in the CURLVLth step of the merge process with TLVLS steps for the CURPBMth problem.

Parameters

in
n

The dimension of the symmetric tridiagonal matrix. n >= 0.

in
tlvls

The total number of merging levels in the overall divide and conquer tree.

in
curlvl

The current level in the overall merge routine, 0 <= curlvl <= tlvls.

in
curpbm

The current problem in the current level in the overall merge routine (counting from upper left to lower right).

in
prmptr

Integer array, dimension (N lg N). Contains a list of pointers which indicate where in PERM a level’s permutation is stored. prmptr[i+1] - prmptr[i] indicates the size of the permutation and incidentally the size of the full, non-deflated problem.

in
perm

Integer array, dimension (N lg N). Contains the permutations (from deflation and sorting) to be applied to each eigenblock.

in
givptr

Integer array, dimension (N lg N). Contains a list of pointers which indicate where in GIVCOL a level’s Givens rotations are stored. givptr[i+1] - givptr[i] indicates the number of Givens rotations.

in
givcol

Integer array, dimension (2, N lg N). Each pair of numbers indicates a pair of columns to take place in a Givens rotation.

in
givnum

Double precision array, dimension (2, N lg N). Each number indicates the S value to be used in the corresponding Givens rotation.

in
Q

Double precision array, dimension (N**2). Contains the square eigenblocks from previous levels, the starting positions for blocks are given by QPTR.

in
qptr

Integer array, dimension (N+2). Contains a list of pointers which indicate where in Q an eigenblock is stored. sqrt(qptr[i+1] - qptr[i]) indicates the size of the block.

out
Z

Double precision array, dimension (N). On output this vector contains the updating vector (the last row of the first sub-eigenvector matrix and the first row of the second sub-eigenvector matrix).

out
ztemp

Double precision array, dimension (N).

out
info

  • = 0: successful exit.

  • < 0: if info = -i, the i-th argument had an illegal value.

Functions

void dlaeda(
    const INT  n,
    const INT  tlvls,
    const INT  curlvl,
    const INT  curpbm,
          INT* prmptr,
          INT* perm,
          INT* givptr,
          INT* givcol,
          f64* givnum,
          f64* Q,
          INT* qptr,
          f64* Z,
          f64* ztemp,
          INT* info
);
void dlaeda(const INT n, const INT tlvls, const INT curlvl, const INT curpbm, INT *prmptr, INT *perm, INT *givptr, INT *givcol, f64 *givnum, f64 *Q, INT *qptr, f64 *Z, f64 *ztemp, INT *info)#

DLAEDA computes the Z vector corresponding to the merge step in the CURLVLth step of the merge process with TLVLS steps for the CURPBMth problem.

Parameters

in
n

The dimension of the symmetric tridiagonal matrix. n >= 0.

in
tlvls

The total number of merging levels in the overall divide and conquer tree.

in
curlvl

The current level in the overall merge routine, 0 <= curlvl <= tlvls.

in
curpbm

The current problem in the current level in the overall merge routine (counting from upper left to lower right).

in
prmptr

Integer array, dimension (N lg N). Contains a list of pointers which indicate where in PERM a level’s permutation is stored. prmptr[i+1] - prmptr[i] indicates the size of the permutation and incidentally the size of the full, non-deflated problem.

in
perm

Integer array, dimension (N lg N). Contains the permutations (from deflation and sorting) to be applied to each eigenblock.

in
givptr

Integer array, dimension (N lg N). Contains a list of pointers which indicate where in GIVCOL a level’s Givens rotations are stored. givptr[i+1] - givptr[i] indicates the number of Givens rotations.

in
givcol

Integer array, dimension (2, N lg N). Each pair of numbers indicates a pair of columns to take place in a Givens rotation.

in
givnum

Double precision array, dimension (2, N lg N). Each number indicates the S value to be used in the corresponding Givens rotation.

in
Q

Double precision array, dimension (N**2). Contains the square eigenblocks from previous levels, the starting positions for blocks are given by QPTR.

in
qptr

Integer array, dimension (N+2). Contains a list of pointers which indicate where in Q an eigenblock is stored. sqrt(qptr[i+1] - qptr[i]) indicates the size of the block.

out
Z

Double precision array, dimension (N). On output this vector contains the updating vector (the last row of the first sub-eigenvector matrix and the first row of the second sub-eigenvector matrix).

out
ztemp

Double precision array, dimension (N).

out
info

  • = 0: successful exit.

  • < 0: if info = -i, the i-th argument had an illegal value.

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