orghr#

Functions

void sorghr(
    const INT  n,
    const INT  ilo,
    const INT  ihi,
          f32* A,
    const INT  lda,
    const f32* tau,
          f32* work,
    const INT  lwork,
          INT* info
);
void sorghr(const INT n, const INT ilo, const INT ihi, f32 *A, const INT lda, const f32 *tau, f32 *work, const INT lwork, INT *info)#

SORGHR generates a real orthogonal matrix Q which is defined as the product of ihi-ilo elementary reflectors of order N, as returned by SGEHRD:

Q = H(ilo) H(ilo+1) … H(ihi-1).

Parameters

in
n

The order of the matrix Q. n >= 0.

in
ilo

ilo and ihi must have the same values as in the previous call of SGEHRD. Q is equal to the unit matrix except in the submatrix Q(ilo+1:ihi, ilo+1:ihi). 0 <= ilo <= ihi <= n-1, if n > 0; ilo=0 and ihi=-1, if n=0. (0-based indexing)

in
ihi

See ilo. (0-based)

inout
A

On entry, the vectors which define the elementary reflectors, as returned by SGEHRD. On exit, the n-by-n orthogonal matrix Q. Dimension (lda, n).

in
lda

The leading dimension of A. lda >= max(1, n).

in
tau

tau(i) must contain the scalar factor of the elementary reflector H(i), as returned by SGEHRD. Dimension (n-1).

out
work

Workspace array, dimension (max(1, lwork)). On exit, if info = 0, work[0] returns the optimal lwork.

in
lwork

The dimension of work. lwork >= ihi-ilo. For optimum performance lwork >= (ihi-ilo)*NB. If lwork = -1, a workspace query is assumed.

out
info

  • = 0: successful exit

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

Functions

void dorghr(
    const INT  n,
    const INT  ilo,
    const INT  ihi,
          f64* A,
    const INT  lda,
    const f64* tau,
          f64* work,
    const INT  lwork,
          INT* info
);
void dorghr(const INT n, const INT ilo, const INT ihi, f64 *A, const INT lda, const f64 *tau, f64 *work, const INT lwork, INT *info)#

DORGHR generates a real orthogonal matrix Q which is defined as the product of ihi-ilo elementary reflectors of order N, as returned by DGEHRD:

Q = H(ilo) H(ilo+1) … H(ihi-1).

Parameters

in
n

The order of the matrix Q. n >= 0.

in
ilo

ilo and ihi must have the same values as in the previous call of DGEHRD. Q is equal to the unit matrix except in the submatrix Q(ilo+1:ihi, ilo+1:ihi). 0 <= ilo <= ihi <= n-1, if n > 0; ilo=0 and ihi=-1, if n=0. (0-based indexing)

in
ihi

See ilo. (0-based)

inout
A

On entry, the vectors which define the elementary reflectors, as returned by DGEHRD. On exit, the n-by-n orthogonal matrix Q. Dimension (lda, n).

in
lda

The leading dimension of A. lda >= max(1, n).

in
tau

tau(i) must contain the scalar factor of the elementary reflector H(i), as returned by DGEHRD. Dimension (n-1).

out
work

Workspace array, dimension (max(1, lwork)). On exit, if info = 0, work[0] returns the optimal lwork.

in
lwork

The dimension of work. lwork >= ihi-ilo. For optimum performance lwork >= (ihi-ilo)*NB. If lwork = -1, a workspace query is assumed.

out
info

  • = 0: successful exit

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

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