table of contents
| hfrk(3) | LAPACK | hfrk(3) |
NAME¶
hfrk - hfrk: Hermitian rank-k update, RFP format
SYNOPSIS¶
Functions¶
subroutine chfrk (transr, uplo, trans, n, k, alpha, a, lda,
beta, c)
CHFRK performs a Hermitian rank-k operation for matrix in RFP format.
subroutine dsfrk (transr, uplo, trans, n, k, alpha, a, lda, beta, c)
DSFRK performs a symmetric rank-k operation for matrix in RFP format.
subroutine ssfrk (transr, uplo, trans, n, k, alpha, a, lda, beta, c)
SSFRK performs a symmetric rank-k operation for matrix in RFP format.
subroutine zhfrk (transr, uplo, trans, n, k, alpha, a, lda, beta, c)
ZHFRK performs a Hermitian rank-k operation for matrix in RFP format.
Detailed Description¶
Function Documentation¶
subroutine chfrk (character transr, character uplo, character trans, integer n, integer k, real alpha, complex, dimension( lda, * ) a, integer lda, real beta, complex, dimension( * ) c)¶
CHFRK performs a Hermitian rank-k operation for matrix in RFP format.
Purpose:
Level 3 BLAS like routine for C in RFP Format.
CHFRK performs one of the Hermitian rank--k operations
C := alpha*A*A**H + beta*C,
or
C := alpha*A**H*A + beta*C,
where alpha and beta are real scalars, C is an n--by--n Hermitian
matrix and A is an n--by--k matrix in the first case and a k--by--n
matrix in the second case.
Parameters
TRANSR
TRANSR is CHARACTER*1
= 'N': The Normal Form of RFP A is stored;
= 'C': The Conjugate-transpose Form of RFP A is stored.
UPLO
UPLO is CHARACTER*1
On entry, UPLO specifies whether the upper or lower
triangular part of the array C is to be referenced as
follows:
UPLO = 'U' or 'u' Only the upper triangular part of C
is to be referenced.
UPLO = 'L' or 'l' Only the lower triangular part of C
is to be referenced.
Unchanged on exit.
TRANS
TRANS is CHARACTER*1
On entry, TRANS specifies the operation to be performed as
follows:
TRANS = 'N' or 'n' C := alpha*A*A**H + beta*C.
TRANS = 'C' or 'c' C := alpha*A**H*A + beta*C.
Unchanged on exit.
N
N is INTEGER
On entry, N specifies the order of the matrix C. N must be
at least zero.
Unchanged on exit.
K
K is INTEGER
On entry with TRANS = 'N' or 'n', K specifies the number
of columns of the matrix A, and on entry with
TRANS = 'C' or 'c', K specifies the number of rows of the
matrix A. K must be at least zero.
Unchanged on exit.
ALPHA
ALPHA is REAL
On entry, ALPHA specifies the scalar alpha.
Unchanged on exit.
A
A is COMPLEX array, dimension (LDA,ka)
where KA
is K when TRANS = 'N' or 'n', and is N otherwise. Before
entry with TRANS = 'N' or 'n', the leading N--by--K part of
the array A must contain the matrix A, otherwise the leading
K--by--N part of the array A must contain the matrix A.
Unchanged on exit.
LDA
LDA is INTEGER
On entry, LDA specifies the first dimension of A as declared
in the calling (sub) program. When TRANS = 'N' or 'n'
then LDA must be at least max( 1, n ), otherwise LDA must
be at least max( 1, k ).
Unchanged on exit.
BETA
BETA is REAL
On entry, BETA specifies the scalar beta.
Unchanged on exit.
C
C is COMPLEX array, dimension (N*(N+1)/2)
On entry, the matrix A in RFP Format. RFP Format is
described by TRANSR, UPLO and N. Note that the imaginary
parts of the diagonal elements need not be set, they are
assumed to be zero, and on exit they are set to zero.
Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
subroutine dsfrk (character transr, character uplo, character trans, integer n, integer k, double precision alpha, double precision, dimension( lda, * ) a, integer lda, double precision beta, double precision, dimension( * ) c)¶
DSFRK performs a symmetric rank-k operation for matrix in RFP format.
Purpose:
Level 3 BLAS like routine for C in RFP Format.
DSFRK performs one of the symmetric rank--k operations
C := alpha*A*A**T + beta*C,
or
C := alpha*A**T*A + beta*C,
where alpha and beta are real scalars, C is an n--by--n symmetric
matrix and A is an n--by--k matrix in the first case and a k--by--n
matrix in the second case.
Parameters
TRANSR
TRANSR is CHARACTER*1
= 'N': The Normal Form of RFP A is stored;
= 'T': The Transpose Form of RFP A is stored.
UPLO
UPLO is CHARACTER*1
On entry, UPLO specifies whether the upper or lower
triangular part of the array C is to be referenced as
follows:
UPLO = 'U' or 'u' Only the upper triangular part of C
is to be referenced.
UPLO = 'L' or 'l' Only the lower triangular part of C
is to be referenced.
Unchanged on exit.
TRANS
TRANS is CHARACTER*1
On entry, TRANS specifies the operation to be performed as
follows:
TRANS = 'N' or 'n' C := alpha*A*A**T + beta*C.
TRANS = 'T' or 't' C := alpha*A**T*A + beta*C.
Unchanged on exit.
N
N is INTEGER
On entry, N specifies the order of the matrix C. N must be
at least zero.
Unchanged on exit.
K
K is INTEGER
On entry with TRANS = 'N' or 'n', K specifies the number
of columns of the matrix A, and on entry with TRANS = 'T'
or 't', K specifies the number of rows of the matrix A. K
must be at least zero.
Unchanged on exit.
ALPHA
ALPHA is DOUBLE PRECISION
On entry, ALPHA specifies the scalar alpha.
Unchanged on exit.
A
A is DOUBLE PRECISION array, dimension (LDA,ka)
where KA
is K when TRANS = 'N' or 'n', and is N otherwise. Before
entry with TRANS = 'N' or 'n', the leading N--by--K part of
the array A must contain the matrix A, otherwise the leading
K--by--N part of the array A must contain the matrix A.
Unchanged on exit.
LDA
LDA is INTEGER
On entry, LDA specifies the first dimension of A as declared
in the calling (sub) program. When TRANS = 'N' or 'n'
then LDA must be at least max( 1, n ), otherwise LDA must
be at least max( 1, k ).
Unchanged on exit.
BETA
BETA is DOUBLE PRECISION
On entry, BETA specifies the scalar beta.
Unchanged on exit.
C
C is DOUBLE PRECISION array, dimension (NT)
NT = N*(N+1)/2. On entry, the symmetric matrix C in RFP
Format. RFP Format is described by TRANSR, UPLO and N.
Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
subroutine ssfrk (character transr, character uplo, character trans, integer n, integer k, real alpha, real, dimension( lda, * ) a, integer lda, real beta, real, dimension( * ) c)¶
SSFRK performs a symmetric rank-k operation for matrix in RFP format.
Purpose:
Level 3 BLAS like routine for C in RFP Format.
SSFRK performs one of the symmetric rank--k operations
C := alpha*A*A**T + beta*C,
or
C := alpha*A**T*A + beta*C,
where alpha and beta are real scalars, C is an n--by--n symmetric
matrix and A is an n--by--k matrix in the first case and a k--by--n
matrix in the second case.
Parameters
TRANSR
TRANSR is CHARACTER*1
= 'N': The Normal Form of RFP A is stored;
= 'T': The Transpose Form of RFP A is stored.
UPLO
UPLO is CHARACTER*1
On entry, UPLO specifies whether the upper or lower
triangular part of the array C is to be referenced as
follows:
UPLO = 'U' or 'u' Only the upper triangular part of C
is to be referenced.
UPLO = 'L' or 'l' Only the lower triangular part of C
is to be referenced.
Unchanged on exit.
TRANS
TRANS is CHARACTER*1
On entry, TRANS specifies the operation to be performed as
follows:
TRANS = 'N' or 'n' C := alpha*A*A**T + beta*C.
TRANS = 'T' or 't' C := alpha*A**T*A + beta*C.
Unchanged on exit.
N
N is INTEGER
On entry, N specifies the order of the matrix C. N must be
at least zero.
Unchanged on exit.
K
K is INTEGER
On entry with TRANS = 'N' or 'n', K specifies the number
of columns of the matrix A, and on entry with TRANS = 'T'
or 't', K specifies the number of rows of the matrix A. K
must be at least zero.
Unchanged on exit.
ALPHA
ALPHA is REAL
On entry, ALPHA specifies the scalar alpha.
Unchanged on exit.
A
A is REAL array, dimension (LDA,ka)
where KA
is K when TRANS = 'N' or 'n', and is N otherwise. Before
entry with TRANS = 'N' or 'n', the leading N--by--K part of
the array A must contain the matrix A, otherwise the leading
K--by--N part of the array A must contain the matrix A.
Unchanged on exit.
LDA
LDA is INTEGER
On entry, LDA specifies the first dimension of A as declared
in the calling (sub) program. When TRANS = 'N' or 'n'
then LDA must be at least max( 1, n ), otherwise LDA must
be at least max( 1, k ).
Unchanged on exit.
BETA
BETA is REAL
On entry, BETA specifies the scalar beta.
Unchanged on exit.
C
C is REAL array, dimension (NT)
NT = N*(N+1)/2. On entry, the symmetric matrix C in RFP
Format. RFP Format is described by TRANSR, UPLO and N.
Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
subroutine zhfrk (character transr, character uplo, character trans, integer n, integer k, double precision alpha, complex*16, dimension( lda, * ) a, integer lda, double precision beta, complex*16, dimension( * ) c)¶
ZHFRK performs a Hermitian rank-k operation for matrix in RFP format.
Purpose:
Level 3 BLAS like routine for C in RFP Format.
ZHFRK performs one of the Hermitian rank--k operations
C := alpha*A*A**H + beta*C,
or
C := alpha*A**H*A + beta*C,
where alpha and beta are real scalars, C is an n--by--n Hermitian
matrix and A is an n--by--k matrix in the first case and a k--by--n
matrix in the second case.
Parameters
TRANSR
TRANSR is CHARACTER*1
= 'N': The Normal Form of RFP A is stored;
= 'C': The Conjugate-transpose Form of RFP A is stored.
UPLO
UPLO is CHARACTER*1
On entry, UPLO specifies whether the upper or lower
triangular part of the array C is to be referenced as
follows:
UPLO = 'U' or 'u' Only the upper triangular part of C
is to be referenced.
UPLO = 'L' or 'l' Only the lower triangular part of C
is to be referenced.
Unchanged on exit.
TRANS
TRANS is CHARACTER*1
On entry, TRANS specifies the operation to be performed as
follows:
TRANS = 'N' or 'n' C := alpha*A*A**H + beta*C.
TRANS = 'C' or 'c' C := alpha*A**H*A + beta*C.
Unchanged on exit.
N
N is INTEGER
On entry, N specifies the order of the matrix C. N must be
at least zero.
Unchanged on exit.
K
K is INTEGER
On entry with TRANS = 'N' or 'n', K specifies the number
of columns of the matrix A, and on entry with
TRANS = 'C' or 'c', K specifies the number of rows of the
matrix A. K must be at least zero.
Unchanged on exit.
ALPHA
ALPHA is DOUBLE PRECISION
On entry, ALPHA specifies the scalar alpha.
Unchanged on exit.
A
A is COMPLEX*16 array, dimension (LDA,ka)
where KA
is K when TRANS = 'N' or 'n', and is N otherwise. Before
entry with TRANS = 'N' or 'n', the leading N--by--K part of
the array A must contain the matrix A, otherwise the leading
K--by--N part of the array A must contain the matrix A.
Unchanged on exit.
LDA
LDA is INTEGER
On entry, LDA specifies the first dimension of A as declared
in the calling (sub) program. When TRANS = 'N' or 'n'
then LDA must be at least max( 1, n ), otherwise LDA must
be at least max( 1, k ).
Unchanged on exit.
BETA
BETA is DOUBLE PRECISION
On entry, BETA specifies the scalar beta.
Unchanged on exit.
C
C is COMPLEX*16 array, dimension (N*(N+1)/2)
On entry, the matrix A in RFP Format. RFP Format is
described by TRANSR, UPLO and N. Note that the imaginary
parts of the diagonal elements need not be set, they are
assumed to be zero, and on exit they are set to zero.
Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Author¶
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