1ZSYMM(1) BLAS routine ZSYMM(1)
2
6 ZSYMM - one of the matrix-matrix operations C := alpha*A*B + beta*C,
7
9 SUBROUTINE ZSYMM(SIDE,UPLO,M,N,ALPHA,A,LDA,B,LDB,BETA,C,LDC)
10 DOUBLE COMPLEX
12 ALPHA,BETA
13 INTEGER LDA,LDB,LDC,M,N
15 CHARACTER SIDE,UPLO
17 DOUBLE COMPLEX
19 A(LDA,*),B(LDB,*),C(LDC,*)
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22 ZSYMM performs one of the matrix-matrix operations
23 or
25 C := alpha*B*A + beta*C,
27 where alpha and beta are scalars, A is a symmetric matrix and B and C
29 are m by n matrices.
30
33 SIDE - CHARACTER*1.
34 On entry, SIDE specifies whether the symmetric matrix A
35 appears on the left or right in the operation as follows:
36 SIDE = 'L' or 'l' C := alpha*A*B + beta*C,
38 SIDE = 'R' or 'r' C := alpha*B*A + beta*C,
40 Unchanged on exit.
42 UPLO - CHARACTER*1.
44 On entry, UPLO specifies whether the upper or lower
45 triangular part of the symmetric matrix A is to be
46 referenced as follows:
47 UPLO = 'U' or 'u' Only the upper triangular part of the sym‐
49 metric matrix is to be referenced.
50 UPLO = 'L' or 'l' Only the lower triangular part of the sym‐
52 metric matrix is to be referenced.
53 Unchanged on exit.
55 M - INTEGER.
57 On entry, M specifies the number of rows of the matrix C. M
58 must be at least zero. Unchanged on exit.
59 N - INTEGER.
61 On entry, N specifies the number of columns of the matrix C. N
62 must be at least zero. Unchanged on exit.
63 ALPHA - COMPLEX*16 .
65 On entry, ALPHA specifies the scalar alpha. Unchanged on exit.
66 A - COMPLEX*16 array of DIMENSION ( LDA, ka ), where ka is
68 m when SIDE = 'L' or 'l' and is n otherwise. Before entry
69 with SIDE = 'L' or 'l', the m by m part of the array A
70 must contain the symmetric matrix, such that when UPLO = 'U'
71 or 'u', the leading m by m upper triangular part of the array A
72 must contain the upper triangular part of the symmetric matrix
73 and the strictly lower triangular part of A is not refer‐
74 enced, and when UPLO = 'L' or 'l', the leading m by m lower
75 triangular part of the array A must contain the lower tri‐
76 angular part of the symmetric matrix and the strictly upper
77 triangular part of A is not referenced. Before entry with
78 SIDE = 'R' or 'r', the n by n part of the array A must con‐
79 tain the symmetric matrix, such that when UPLO = 'U' or 'u',
80 the leading n by n upper triangular part of the array A must
81 contain the upper triangular part of the symmetric matrix and
82 the strictly lower triangular part of A is not referenced,
83 and when UPLO = 'L' or 'l', the leading n by n lower triangu‐
84 lar part of the array A must contain the lower triangular
85 part of the symmetric matrix and the strictly upper triangu‐
86 lar part of A is not referenced. Unchanged on exit.
87 LDA - INTEGER.
89 On entry, LDA specifies the first dimension of A as declared in
90 the calling (sub) program. When SIDE = 'L' or 'l' then LDA
91 must be at least max( 1, m ), otherwise LDA must be at least
92 max( 1, n ). Unchanged on exit.
93 B - COMPLEX*16 array of DIMENSION ( LDB, n ).
95 Before entry, the leading m by n part of the array B must
96 contain the matrix B. Unchanged on exit.
97 LDB - INTEGER.
99 On entry, LDB specifies the first dimension of B as declared in
100 the calling (sub) program. LDB must be at least max( 1,
101 m ). Unchanged on exit.
102 BETA - COMPLEX*16 .
104 On entry, BETA specifies the scalar beta. When BETA is
105 supplied as zero then C need not be set on input. Unchanged on
106 exit.
107 C - COMPLEX*16 array of DIMENSION ( LDC, n ).
109 Before entry, the leading m by n part of the array C must
110 contain the matrix C, except when beta is zero, in which
111 case C need not be set on entry. On exit, the array C is
112 overwritten by the m by n updated matrix.
113 LDC - INTEGER.
115 On entry, LDC specifies the first dimension of C as declared in
116 the calling (sub) program. LDC must be at least max( 1,
117 m ). Unchanged on exit.
118 Level 3 Blas routine.
120 -- Written on 8-February-1989. Jack Dongarra, Argonne National
122 Laboratory. Iain Duff, AERE Harwell. Jeremy Du Croz, Numerical
123 Algorithms Group Ltd. Sven Hammarling, Numerical Algorithms
124 Group Ltd.
125BLAS routine November 2006 ZSYMM(1)