1ZSYMM(1) BLAS routine ZSYMM(1)
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6 ZSYMM - performs one of the matrix-matrix operations C := alpha*A*B +
7 beta*C,
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10 SUBROUTINE ZSYMM(SIDE,UPLO,M,N,ALPHA,A,LDA,B,LDB,BETA,C,LDC)
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12 DOUBLE COMPLEX
13 ALPHA,BETA
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15 INTEGER LDA,LDB,LDC,M,N
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17 CHARACTER SIDE,UPLO
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19 DOUBLE COMPLEX
20 A(LDA,*),B(LDB,*),C(LDC,*)
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23 ZSYMM performs one of the matrix-matrix operations
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25 or
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27 C := alpha*B*A + beta*C,
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29 where alpha and beta are scalars, A is a symmetric matrix and B and C
30 are m by n matrices.
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34 SIDE - CHARACTER*1.
35 On entry, SIDE specifies whether the symmetric matrix A
36 appears on the left or right in the operation as follows:
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38 SIDE = 'L' or 'l' C := alpha*A*B + beta*C,
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40 SIDE = 'R' or 'r' C := alpha*B*A + beta*C,
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42 Unchanged on exit.
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44 UPLO - CHARACTER*1.
45 On entry, UPLO specifies whether the upper or lower
46 triangular part of the symmetric matrix A is to be
47 referenced as follows:
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49 UPLO = 'U' or 'u' Only the upper triangular part of the sym‐
50 metric matrix is to be referenced.
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52 UPLO = 'L' or 'l' Only the lower triangular part of the sym‐
53 metric matrix is to be referenced.
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55 Unchanged on exit.
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57 M - INTEGER.
58 On entry, M specifies the number of rows of the matrix C. M
59 must be at least zero. Unchanged on exit.
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61 N - INTEGER.
62 On entry, N specifies the number of columns of the matrix C. N
63 must be at least zero. Unchanged on exit.
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65 ALPHA - COMPLEX*16 .
66 On entry, ALPHA specifies the scalar alpha. Unchanged on exit.
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68 A - COMPLEX*16 array of DIMENSION ( LDA, ka ), where ka is
69 m when SIDE = 'L' or 'l' and is n otherwise. Before entry
70 with SIDE = 'L' or 'l', the m by m part of the array A
71 must contain the symmetric matrix, such that when UPLO = 'U'
72 or 'u', the leading m by m upper triangular part of the array A
73 must contain the upper triangular part of the symmetric matrix
74 and the strictly lower triangular part of A is not refer‐
75 enced, and when UPLO = 'L' or 'l', the leading m by m lower
76 triangular part of the array A must contain the lower tri‐
77 angular part of the symmetric matrix and the strictly upper
78 triangular part of A is not referenced. Before entry with
79 SIDE = 'R' or 'r', the n by n part of the array A must con‐
80 tain the symmetric matrix, such that when UPLO = 'U' or 'u',
81 the leading n by n upper triangular part of the array A must
82 contain the upper triangular part of the symmetric matrix and
83 the strictly lower triangular part of A is not referenced,
84 and when UPLO = 'L' or 'l', the leading n by n lower triangu‐
85 lar part of the array A must contain the lower triangular
86 part of the symmetric matrix and the strictly upper triangu‐
87 lar part of A is not referenced. Unchanged on exit.
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89 LDA - INTEGER.
90 On entry, LDA specifies the first dimension of A as declared in
91 the calling (sub) program. When SIDE = 'L' or 'l' then LDA
92 must be at least max( 1, m ), otherwise LDA must be at least
93 max( 1, n ). Unchanged on exit.
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95 B - COMPLEX*16 array of DIMENSION ( LDB, n ).
96 Before entry, the leading m by n part of the array B must
97 contain the matrix B. Unchanged on exit.
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99 LDB - INTEGER.
100 On entry, LDB specifies the first dimension of B as declared in
101 the calling (sub) program. LDB must be at least max( 1,
102 m ). Unchanged on exit.
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104 BETA - COMPLEX*16 .
105 On entry, BETA specifies the scalar beta. When BETA is
106 supplied as zero then C need not be set on input. Unchanged on
107 exit.
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109 C - COMPLEX*16 array of DIMENSION ( LDC, n ).
110 Before entry, the leading m by n part of the array C must
111 contain the matrix C, except when beta is zero, in which
112 case C need not be set on entry. On exit, the array C is
113 overwritten by the m by n updated matrix.
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115 LDC - INTEGER.
116 On entry, LDC specifies the first dimension of C as declared in
117 the calling (sub) program. LDC must be at least max( 1,
118 m ). Unchanged on exit.
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121 Level 3 Blas routine.
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123 -- Written on 8-February-1989.
124 Jack Dongarra, Argonne National Laboratory.
125 Iain Duff, AERE Harwell.
126 Jeremy Du Croz, Numerical Algorithms Group Ltd.
127 Sven Hammarling, Numerical Algorithms Group Ltd.
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132BLAS routine November 2008 ZSYMM(1)