1CHFRK(1)LAPACK routine (version 3.2) CHFRK(1)
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6 CHFRK - 3 BLAS like routine for C in RFP Format
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9 SUBROUTINE CHFRK( TRANSR, UPLO, TRANS, N, K, ALPHA, A, LDA, BETA,
10 + C )
12 REAL ALPHA, BETA
14 INTEGER K, LDA, N
16 CHARACTER TRANS, TRANSR, UPLO
18 COMPLEX A( LDA, * ), C( * )
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22 Level 3 BLAS like routine for C in RFP Format. CHFRK performs one of
23 the Hermitian rank--k operations
24 C := alpha*A*conjg( A' ) + beta*C,
25 or
26 C := alpha*conjg( A' )*A + beta*C,
27 where alpha and beta are real scalars, C is an n--by--n Hermitian
28 matrix and A is an n--by--k matrix in the first case and a k--by--n
29 matrix in the second case.
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32 TRANSR - (input) CHARACTER. = 'N': The Normal Form of RFP A is
33 stored;
34 = 'C': The Conjugate-transpose Form of RFP A is stored.
35 UPLO - (input) CHARACTER.
37 On entry, UPLO specifies whether the upper or lower
38 triangular part of the array C is to be referenced as
39 follows: UPLO = 'U' or 'u' Only the upper triangular part of
40 C is to be referenced. UPLO = 'L' or 'l' Only the lower tri‐
41 angular part of C is to be referenced. Unchanged on exit.
42 TRANS - (input) CHARACTER.
44 On entry, TRANS specifies the operation to be performed as
45 follows: TRANS = 'N' or 'n' C := alpha*A*conjg( A' ) + beta*C.
46 TRANS = 'C' or 'c' C := alpha*conjg( A' )*A + beta*C.
47 Unchanged on exit.
48 N - (input) INTEGER.
50 On entry, N specifies the order of the matrix C. N must be at
51 least zero. Unchanged on exit.
52 K - (input) INTEGER.
54 On entry with TRANS = 'N' or 'n', K specifies the number of
55 columns of the matrix A, and on entry with TRANS =
56 'C' or 'c', K specifies the number of rows of the matrix A.
57 K must be at least zero. Unchanged on exit.
58 ALPHA - (input) REAL.
60 On entry, ALPHA specifies the scalar alpha. Unchanged on exit.
61 A - (input) COMPLEX array of DIMENSION ( LDA, ka ), where KA
63 is K when TRANS = 'N' or 'n', and is N otherwise. Before entry
64 with TRANS = 'N' or 'n', the leading N--by--K part of the array
65 A must contain the matrix A, otherwise the leading K--by--N part
66 of the array A must contain the matrix A. Unchanged on exit.
67 LDA - (input) INTEGER.
69 On entry, LDA specifies the first dimension of A as declared in
70 the calling (sub) program. When TRANS = 'N' or 'n' then
71 LDA must be at least max( 1, n ), otherwise LDA must be at
72 least max( 1, k ). Unchanged on exit.
73 BETA - (input) REAL.
75 On entry, BETA specifies the scalar beta. Unchanged on exit.
76 C - (input/output) COMPLEX array, dimension ( N*(N+1)/2 ).
78 On entry, the matrix A in RFP Format. RFP Format is described by
79 TRANSR, UPLO and N. Note that the imaginary parts of the diago‐
80 nal elements need not be set, they are assumed to be zero, and
81 on exit they are set to zero.
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84 LAPACK routine (version 3.2) November 2008 CHFRK(1)