ungtr#

cungtr

Functions

void cungtr(
    const char*          uplo,
    const INT            n,
          c64*  restrict A,
    const INT            lda,
    const c64*  restrict tau,
          c64*  restrict work,
    const INT            lwork,
          INT*           info
);

void cungtr(const char *uplo, const INT n, c64 *restrict A, const INT lda, const c64 *restrict tau, c64 *restrict work, const INT lwork, INT *info)#

CUNGTR generates a complex unitary matrix Q which is defined as the product of n-1 elementary reflectors of order N, as returned by CHETRD:

if UPLO = ‘U’, Q = H(n-1) … H(2) H(1),

if UPLO = ‘L’, Q = H(1) H(2) … H(n-1).

Parameters

in

uplo

= ‘U’: Upper triangle of A contains elementary reflectors from CHETRD; = ‘L’: Lower triangle of A contains elementary reflectors from CHETRD.

in

n

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

inout

A

Complex*16 array, dimension (lda, n). On entry, the vectors which define the elementary reflectors, as returned by CHETRD. On exit, the N-by-N unitary matrix Q.

in

lda

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

in

tau

Complex*16 array, dimension (n-1). TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by CHETRD.

out

work

Complex*16 array, dimension (max(1, lwork)). On exit, if info = 0, work[0] returns the optimal lwork.

in

lwork

The dimension of the array work. lwork >= max(1, n-1). For optimum performance lwork >= (n-1)*nb, where nb is the optimal blocksize. If lwork = -1, then a workspace query is assumed.

out

info

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

zungtr

Functions

void zungtr(
    const char*          uplo,
    const INT            n,
          c128* restrict A,
    const INT            lda,
    const c128* restrict tau,
          c128* restrict work,
    const INT            lwork,
          INT*           info
);

void zungtr(const char *uplo, const INT n, c128 *restrict A, const INT lda, const c128 *restrict tau, c128 *restrict work, const INT lwork, INT *info)#

ZUNGTR generates a complex unitary matrix Q which is defined as the product of n-1 elementary reflectors of order N, as returned by ZHETRD:

if UPLO = ‘U’, Q = H(n-1) … H(2) H(1),

if UPLO = ‘L’, Q = H(1) H(2) … H(n-1).

Parameters

in

uplo

= ‘U’: Upper triangle of A contains elementary reflectors from ZHETRD; = ‘L’: Lower triangle of A contains elementary reflectors from ZHETRD.

in

n

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

inout

A

Complex*16 array, dimension (lda, n). On entry, the vectors which define the elementary reflectors, as returned by ZHETRD. On exit, the N-by-N unitary matrix Q.

in

lda

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

in

tau

Complex*16 array, dimension (n-1). TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by ZHETRD.

out

work

Complex*16 array, dimension (max(1, lwork)). On exit, if info = 0, work[0] returns the optimal lwork.

in

lwork

The dimension of the array work. lwork >= max(1, n-1). For optimum performance lwork >= (n-1)*nb, where nb is the optimal blocksize. If lwork = -1, then a workspace query is assumed.

out

info

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

ungtr#

This Page