dsfrk.f man page

dsfrk.f —

Synopsis

Functions/Subroutines

subroutine dsfrk (TRANSR, UPLO, TRANS, N, K, ALPHA, A, LDA, BETA, C)
DSFRK performs a symmetric rank-k operation for matrix in RFP format.

Function/Subroutine Documentation

subroutine dsfrk (characterTRANSR, characterUPLO, characterTRANS, integerN, integerK, double precisionALPHA, double precision, dimension( lda, * )A, integerLDA, double precisionBETA, 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.

Date:

September 2012

Definition at line 166 of file dsfrk.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.

Referenced By

dsfrk(3) is an alias of dsfrk.f(3).

Sat Nov 16 2013 Version 3.4.2 LAPACK