1CSYMM(1) BLAS routine CSYMM(1)
2
6 CSYMM - one of the matrix-matrix operations C := alpha*A*B + beta*C,
7
9 SUBROUTINE CSYMM(SIDE,UPLO,M,N,ALPHA,A,LDA,B,LDB,BETA,C,LDC)
10 COMPLEX ALPHA,BETA
12 INTEGER LDA,LDB,LDC,M,N
14 CHARACTER SIDE,UPLO
16 COMPLEX A(LDA,*),B(LDB,*),C(LDC,*)
18
20 CSYMM performs one of the matrix-matrix operations
21 or
23 C := alpha*B*A + beta*C,
25 where alpha and beta are scalars, A is a symmetric matrix and B and C
27 are m by n matrices.
28
31 SIDE - CHARACTER*1.
32 On entry, SIDE specifies whether the symmetric matrix A
33 appears on the left or right in the operation as follows:
34 SIDE = 'L' or 'l' C := alpha*A*B + beta*C,
36 SIDE = 'R' or 'r' C := alpha*B*A + beta*C,
38 Unchanged on exit.
40 UPLO - CHARACTER*1.
42 On entry, UPLO specifies whether the upper or lower
43 triangular part of the symmetric matrix A is to be
44 referenced as follows:
45 UPLO = 'U' or 'u' Only the upper triangular part of the sym‐
47 metric matrix is to be referenced.
48 UPLO = 'L' or 'l' Only the lower triangular part of the sym‐
50 metric matrix is to be referenced.
51 Unchanged on exit.
53 M - INTEGER.
55 On entry, M specifies the number of rows of the matrix C. M
56 must be at least zero. Unchanged on exit.
57 N - INTEGER.
59 On entry, N specifies the number of columns of the matrix C. N
60 must be at least zero. Unchanged on exit.
61 ALPHA - COMPLEX .
63 On entry, ALPHA specifies the scalar alpha. Unchanged on exit.
64 A - COMPLEX array of DIMENSION ( LDA, ka ), where ka is
66 m when SIDE = 'L' or 'l' and is n otherwise. Before entry
67 with SIDE = 'L' or 'l', the m by m part of the array A
68 must contain the symmetric matrix, such that when UPLO = 'U'
69 or 'u', the leading m by m upper triangular part of the array A
70 must contain the upper triangular part of the symmetric matrix
71 and the strictly lower triangular part of A is not refer‐
72 enced, and when UPLO = 'L' or 'l', the leading m by m lower
73 triangular part of the array A must contain the lower tri‐
74 angular part of the symmetric matrix and the strictly upper
75 triangular part of A is not referenced. Before entry with
76 SIDE = 'R' or 'r', the n by n part of the array A must con‐
77 tain the symmetric matrix, such that when UPLO = 'U' or 'u',
78 the leading n by n upper triangular part of the array A must
79 contain the upper triangular part of the symmetric matrix and
80 the strictly lower triangular part of A is not referenced,
81 and when UPLO = 'L' or 'l', the leading n by n lower triangu‐
82 lar part of the array A must contain the lower triangular
83 part of the symmetric matrix and the strictly upper triangu‐
84 lar part of A is not referenced. Unchanged on exit.
85 LDA - INTEGER.
87 On entry, LDA specifies the first dimension of A as declared in
88 the calling (sub) program. When SIDE = 'L' or 'l' then LDA
89 must be at least max( 1, m ), otherwise LDA must be at least
90 max( 1, n ). Unchanged on exit.
91 B - COMPLEX array of DIMENSION ( LDB, n ).
93 Before entry, the leading m by n part of the array B must
94 contain the matrix B. Unchanged on exit.
95 LDB - INTEGER.
97 On entry, LDB specifies the first dimension of B as declared in
98 the calling (sub) program. LDB must be at least max( 1,
99 m ). Unchanged on exit.
100 BETA - COMPLEX .
102 On entry, BETA specifies the scalar beta. When BETA is
103 supplied as zero then C need not be set on input. Unchanged on
104 exit.
105 C - COMPLEX array of DIMENSION ( LDC, n ).
107 Before entry, the leading m by n part of the array C must
108 contain the matrix C, except when beta is zero, in which
109 case C need not be set on entry. On exit, the array C is
110 overwritten by the m by n updated matrix.
111 LDC - INTEGER.
113 On entry, LDC specifies the first dimension of C as declared in
114 the calling (sub) program. LDC must be at least max( 1,
115 m ). Unchanged on exit.
116 Level 3 Blas routine.
118 -- Written on 8-February-1989. Jack Dongarra, Argonne National
120 Laboratory. Iain Duff, AERE Harwell. Jeremy Du Croz, Numerical
121 Algorithms Group Ltd. Sven Hammarling, Numerical Algorithms
122 Group Ltd.
123BLAS routine November 2006 CSYMM(1)