1CTRMM(1) BLAS routine CTRMM(1)
2
6 CTRMM - performs one of the matrix-matrix operations B := alpha*op( A
7 )*B, or B := alpha*B*op( A ) where alpha is a scalar, B is an m by n
8 matrix, A is a unit, or non-unit, upper or lower triangular matrix and
9 op( A ) is one of op( A ) = A or op( A ) = A' or op( A ) = conjg( A'
10 )
11
13 SUBROUTINE CTRMM(SIDE,UPLO,TRANSA,DIAG,M,N,ALPHA,A,LDA,B,LDB)
14 COMPLEX ALPHA
16 INTEGER LDA,LDB,M,N
18 CHARACTER DIAG,SIDE,TRANSA,UPLO
20 COMPLEX A(LDA,*),B(LDB,*)
22
24 CTRMM performs one of the matrix-matrix operations
25
28 SIDE - CHARACTER*1.
29 On entry, SIDE specifies whether op( A ) multiplies B from the
30 left or right as follows:
31 SIDE = 'L' or 'l' B := alpha*op( A )*B.
33 SIDE = 'R' or 'r' B := alpha*B*op( A ).
35 Unchanged on exit.
37 UPLO - CHARACTER*1.
39 On entry, UPLO specifies whether the matrix A is an upper or
40 lower triangular matrix as follows:
41 UPLO = 'U' or 'u' A is an upper triangular matrix.
43 UPLO = 'L' or 'l' A is a lower triangular matrix.
45 Unchanged on exit.
47 TRANSA - CHARACTER*1. On entry, TRANSA specifies the form of
49 op( A ) to be used in the matrix multiplication as follows:
50 TRANSA = 'N' or 'n' op( A ) = A.
52 TRANSA = 'T' or 't' op( A ) = A'.
54 TRANSA = 'C' or 'c' op( A ) = conjg( A' ).
56 Unchanged on exit.
58 DIAG - CHARACTER*1.
60 On entry, DIAG specifies whether or not A is unit triangular as
61 follows:
62 DIAG = 'U' or 'u' A is assumed to be unit triangular.
64 DIAG = 'N' or 'n' A is not assumed to be unit triangular.
66 Unchanged on exit.
68 M - INTEGER.
70 On entry, M specifies the number of rows of B. M must be at
71 least zero. Unchanged on exit.
72 N - INTEGER.
74 On entry, N specifies the number of columns of B. N must be at
75 least zero. Unchanged on exit.
76 ALPHA - COMPLEX .
78 On entry, ALPHA specifies the scalar alpha. When alpha is
79 zero then A is not referenced and B need not be set before
80 entry. Unchanged on exit.
81 A - COMPLEX array of DIMENSION ( LDA, k ), where k is m
83 when SIDE = 'L' or 'l' and is n when SIDE = 'R' or 'r'.
84 Before entry with UPLO = 'U' or 'u', the leading k by k
85 upper triangular part of the array A must contain the upper
86 triangular matrix and the strictly lower triangular part of A
87 is not referenced. Before entry with UPLO = 'L' or 'l', the
88 leading k by k lower triangular part of the array A must con‐
89 tain the lower triangular matrix and the strictly upper trian‐
90 gular part of A is not referenced. Note that when DIAG = 'U'
91 or 'u', the diagonal elements of A are not referenced either,
92 but are assumed to be unity. Unchanged on exit.
93 LDA - INTEGER.
95 On entry, LDA specifies the first dimension of A as declared in
96 the calling (sub) program. When SIDE = 'L' or 'l' then LDA
97 must be at least max( 1, m ), when SIDE = 'R' or 'r' then LDA
98 must be at least max( 1, n ). Unchanged on exit.
99 B - COMPLEX array of DIMENSION ( LDB, n ).
101 Before entry, the leading m by n part of the array B must
102 contain the matrix B, and on exit is overwritten by the
103 transformed matrix.
104 LDB - INTEGER.
106 On entry, LDB specifies the first dimension of B as declared in
107 the calling (sub) program. LDB must be at least max( 1,
108 m ). Unchanged on exit.
109
111 Level 3 Blas routine.
112 -- Written on 8-February-1989.
114 Jack Dongarra, Argonne National Laboratory.
115 Iain Duff, AERE Harwell.
116 Jeremy Du Croz, Numerical Algorithms Group Ltd.
117 Sven Hammarling, Numerical Algorithms Group Ltd.
118BLAS routine November 2008 CTRMM(1)