lauum(3) LAPACK lauum(3)
NAME
lauum - lauum: triangular multiply: U^H U
SYNOPSIS
Functions
subroutine clauum (uplo, n, a, lda, info)
CLAUUM computes the product UUH or LHL, where U and L are upper or
lower triangular matrices (blocked algorithm).
subroutine dlauum (uplo, n, a, lda, info)
DLAUUM computes the product UUH or LHL, where U and L are upper or
lower triangular matrices (blocked algorithm).
subroutine slauum (uplo, n, a, lda, info)
SLAUUM computes the product UUH or LHL, where U and L are upper or
lower triangular matrices (blocked algorithm).
subroutine zlauum (uplo, n, a, lda, info)
ZLAUUM computes the product UUH or LHL, where U and L are upper or
lower triangular matrices (blocked algorithm).
Detailed Description
Function Documentation
subroutine clauum (character uplo, integer n, complex, dimension( lda, * )
a, integer lda, integer info)
CLAUUM computes the product UUH or LHL, where U and L are upper or lower
triangular matrices (blocked algorithm).
Purpose:
CLAUUM computes the product U * U**H or L**H * L, where the triangular
factor U or L is stored in the upper or lower triangular part of
the array A.
If UPLO = 'U' or 'u' then the upper triangle of the result is stored,
overwriting the factor U in A.
If UPLO = 'L' or 'l' then the lower triangle of the result is stored,
overwriting the factor L in A.
This is the blocked form of the algorithm, calling Level 3 BLAS.
Parameters
UPLO
UPLO is CHARACTER*1
Specifies whether the triangular factor stored in the array A
is upper or lower triangular:
= 'U': Upper triangular
= 'L': Lower triangular
N
N is INTEGER
The order of the triangular factor U or L. N >= 0.
A
A is COMPLEX array, dimension (LDA,N)
On entry, the triangular factor U or L.
On exit, if UPLO = 'U', the upper triangle of A is
overwritten with the upper triangle of the product U * U**H;
if UPLO = 'L', the lower triangle of A is overwritten with
the lower triangle of the product L**H * L.
LDA
LDA is INTEGER
The leading dimension of the array A. LDA >= max(1,N).
INFO
INFO is INTEGER
= 0: successful exit
< 0: if INFO = -k, the k-th argument had an illegal value
Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
subroutine dlauum (character uplo, integer n, double precision, dimension(
lda, * ) a, integer lda, integer info)
DLAUUM computes the product UUH or LHL, where U and L are upper or lower
triangular matrices (blocked algorithm).
Purpose:
DLAUUM computes the product U * U**T or L**T * L, where the triangular
factor U or L is stored in the upper or lower triangular part of
the array A.
If UPLO = 'U' or 'u' then the upper triangle of the result is stored,
overwriting the factor U in A.
If UPLO = 'L' or 'l' then the lower triangle of the result is stored,
overwriting the factor L in A.
This is the blocked form of the algorithm, calling Level 3 BLAS.
Parameters
UPLO
UPLO is CHARACTER*1
Specifies whether the triangular factor stored in the array A
is upper or lower triangular:
= 'U': Upper triangular
= 'L': Lower triangular
N
N is INTEGER
The order of the triangular factor U or L. N >= 0.
A
A is DOUBLE PRECISION array, dimension (LDA,N)
On entry, the triangular factor U or L.
On exit, if UPLO = 'U', the upper triangle of A is
overwritten with the upper triangle of the product U * U**T;
if UPLO = 'L', the lower triangle of A is overwritten with
the lower triangle of the product L**T * L.
LDA
LDA is INTEGER
The leading dimension of the array A. LDA >= max(1,N).
INFO
INFO is INTEGER
= 0: successful exit
< 0: if INFO = -k, the k-th argument had an illegal value
Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
subroutine slauum (character uplo, integer n, real, dimension( lda, * ) a,
integer lda, integer info)
SLAUUM computes the product UUH or LHL, where U and L are upper or lower
triangular matrices (blocked algorithm).
Purpose:
SLAUUM computes the product U * U**T or L**T * L, where the triangular
factor U or L is stored in the upper or lower triangular part of
the array A.
If UPLO = 'U' or 'u' then the upper triangle of the result is stored,
overwriting the factor U in A.
If UPLO = 'L' or 'l' then the lower triangle of the result is stored,
overwriting the factor L in A.
This is the blocked form of the algorithm, calling Level 3 BLAS.
Parameters
UPLO
UPLO is CHARACTER*1
Specifies whether the triangular factor stored in the array A
is upper or lower triangular:
= 'U': Upper triangular
= 'L': Lower triangular
N
N is INTEGER
The order of the triangular factor U or L. N >= 0.
A
A is REAL array, dimension (LDA,N)
On entry, the triangular factor U or L.
On exit, if UPLO = 'U', the upper triangle of A is
overwritten with the upper triangle of the product U * U**T;
if UPLO = 'L', the lower triangle of A is overwritten with
the lower triangle of the product L**T * L.
LDA
LDA is INTEGER
The leading dimension of the array A. LDA >= max(1,N).
INFO
INFO is INTEGER
= 0: successful exit
< 0: if INFO = -k, the k-th argument had an illegal value
Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
subroutine zlauum (character uplo, integer n, complex*16, dimension( lda, *
) a, integer lda, integer info)
ZLAUUM computes the product UUH or LHL, where U and L are upper or lower
triangular matrices (blocked algorithm).
Purpose:
ZLAUUM computes the product U * U**H or L**H * L, where the triangular
factor U or L is stored in the upper or lower triangular part of
the array A.
If UPLO = 'U' or 'u' then the upper triangle of the result is stored,
overwriting the factor U in A.
If UPLO = 'L' or 'l' then the lower triangle of the result is stored,
overwriting the factor L in A.
This is the blocked form of the algorithm, calling Level 3 BLAS.
Parameters
UPLO
UPLO is CHARACTER*1
Specifies whether the triangular factor stored in the array A
is upper or lower triangular:
= 'U': Upper triangular
= 'L': Lower triangular
N
N is INTEGER
The order of the triangular factor U or L. N >= 0.
A
A is COMPLEX*16 array, dimension (LDA,N)
On entry, the triangular factor U or L.
On exit, if UPLO = 'U', the upper triangle of A is
overwritten with the upper triangle of the product U * U**H;
if UPLO = 'L', the lower triangle of A is overwritten with
the lower triangle of the product L**H * L.
LDA
LDA is INTEGER
The leading dimension of the array A. LDA >= max(1,N).
INFO
INFO is INTEGER
= 0: successful exit
< 0: if INFO = -k, the k-th argument had an illegal value
Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Author
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