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NAME
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
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