upgtr - Man Page

subroutine cupgtr (uplo, n, ap, tau, q, ldq, work, info)
CUPGTR
subroutine dopgtr (uplo, n, ap, tau, q, ldq, work, info)
DOPGTR
subroutine sopgtr (uplo, n, ap, tau, q, ldq, work, info)
SOPGTR
subroutine zupgtr (uplo, n, ap, tau, q, ldq, work, info)
ZUPGTR

CUPGTR  

Purpose:

 CUPGTR generates a complex unitary matrix Q which is defined as the
 product of n-1 elementary reflectors H(i) of order n, as returned by
 CHPTRD using packed storage:

 if UPLO = 'U', Q = H(n-1) . . . H(2) H(1),

 if UPLO = 'L', Q = H(1) H(2) . . . H(n-1).

Parameters

UPLO

          UPLO is CHARACTER*1
          = 'U': Upper triangular packed storage used in previous
                 call to CHPTRD;
          = 'L': Lower triangular packed storage used in previous
                 call to CHPTRD.

N

          N is INTEGER
          The order of the matrix Q. N >= 0.

AP

          AP is COMPLEX array, dimension (N*(N+1)/2)
          The vectors which define the elementary reflectors, as
          returned by CHPTRD.

TAU

          TAU is COMPLEX array, dimension (N-1)
          TAU(i) must contain the scalar factor of the elementary
          reflector H(i), as returned by CHPTRD.

Q

          Q is COMPLEX array, dimension (LDQ,N)
          The N-by-N unitary matrix Q.

LDQ

          LDQ is INTEGER
          The leading dimension of the array Q. LDQ >= max(1,N).

WORK

          WORK is COMPLEX array, dimension (N-1)

INFO

          INFO is INTEGER
          = 0:  successful exit
          < 0:  if INFO = -i, the i-th argument had an illegal value

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line 113 of file cupgtr.f.

DOPGTR  

Purpose:

 DOPGTR generates a real orthogonal matrix Q which is defined as the
 product of n-1 elementary reflectors H(i) of order n, as returned by
 DSPTRD using packed storage:

 if UPLO = 'U', Q = H(n-1) . . . H(2) H(1),

 if UPLO = 'L', Q = H(1) H(2) . . . H(n-1).

Parameters

UPLO

          UPLO is CHARACTER*1
          = 'U': Upper triangular packed storage used in previous
                 call to DSPTRD;
          = 'L': Lower triangular packed storage used in previous
                 call to DSPTRD.

N

          N is INTEGER
          The order of the matrix Q. N >= 0.

AP

          AP is DOUBLE PRECISION array, dimension (N*(N+1)/2)
          The vectors which define the elementary reflectors, as
          returned by DSPTRD.

TAU

          TAU is DOUBLE PRECISION array, dimension (N-1)
          TAU(i) must contain the scalar factor of the elementary
          reflector H(i), as returned by DSPTRD.

Q

          Q is DOUBLE PRECISION array, dimension (LDQ,N)
          The N-by-N orthogonal matrix Q.

LDQ

          LDQ is INTEGER
          The leading dimension of the array Q. LDQ >= max(1,N).

WORK

          WORK is DOUBLE PRECISION array, dimension (N-1)

INFO

          INFO is INTEGER
          = 0:  successful exit
          < 0:  if INFO = -i, the i-th argument had an illegal value

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line 113 of file dopgtr.f.

SOPGTR  

Purpose:

 SOPGTR generates a real orthogonal matrix Q which is defined as the
 product of n-1 elementary reflectors H(i) of order n, as returned by
 SSPTRD using packed storage:

 if UPLO = 'U', Q = H(n-1) . . . H(2) H(1),

 if UPLO = 'L', Q = H(1) H(2) . . . H(n-1).

Parameters

UPLO

          UPLO is CHARACTER*1
          = 'U': Upper triangular packed storage used in previous
                 call to SSPTRD;
          = 'L': Lower triangular packed storage used in previous
                 call to SSPTRD.

N

          N is INTEGER
          The order of the matrix Q. N >= 0.

AP

          AP is REAL array, dimension (N*(N+1)/2)
          The vectors which define the elementary reflectors, as
          returned by SSPTRD.

TAU

          TAU is REAL array, dimension (N-1)
          TAU(i) must contain the scalar factor of the elementary
          reflector H(i), as returned by SSPTRD.

Q

          Q is REAL array, dimension (LDQ,N)
          The N-by-N orthogonal matrix Q.

LDQ

          LDQ is INTEGER
          The leading dimension of the array Q. LDQ >= max(1,N).

WORK

          WORK is REAL array, dimension (N-1)

INFO

          INFO is INTEGER
          = 0:  successful exit
          < 0:  if INFO = -i, the i-th argument had an illegal value

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line 113 of file sopgtr.f.

ZUPGTR  

Purpose:

 ZUPGTR generates a complex unitary matrix Q which is defined as the
 product of n-1 elementary reflectors H(i) of order n, as returned by
 ZHPTRD using packed storage:

 if UPLO = 'U', Q = H(n-1) . . . H(2) H(1),

 if UPLO = 'L', Q = H(1) H(2) . . . H(n-1).

Parameters

UPLO

          UPLO is CHARACTER*1
          = 'U': Upper triangular packed storage used in previous
                 call to ZHPTRD;
          = 'L': Lower triangular packed storage used in previous
                 call to ZHPTRD.

N

          N is INTEGER
          The order of the matrix Q. N >= 0.

AP

          AP is COMPLEX*16 array, dimension (N*(N+1)/2)
          The vectors which define the elementary reflectors, as
          returned by ZHPTRD.

TAU

          TAU is COMPLEX*16 array, dimension (N-1)
          TAU(i) must contain the scalar factor of the elementary
          reflector H(i), as returned by ZHPTRD.

Q

          Q is COMPLEX*16 array, dimension (LDQ,N)
          The N-by-N unitary matrix Q.

LDQ

          LDQ is INTEGER
          The leading dimension of the array Q. LDQ >= max(1,N).

WORK

          WORK is COMPLEX*16 array, dimension (N-1)

INFO

          INFO is INTEGER
          = 0:  successful exit
          < 0:  if INFO = -i, the i-th argument had an illegal value

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line 113 of file zupgtr.f.