1CSYMV(1)            LAPACK auxiliary routine (version 3.1)            CSYMV(1)
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NAME

6       CSYMV - the matrix-vector operation   y := alpha*A*x + beta*y,
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SYNOPSIS

9       SUBROUTINE CSYMV( UPLO, N, ALPHA, A, LDA, X, INCX, BETA, Y, INCY )
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11           CHARACTER     UPLO
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13           INTEGER       INCX, INCY, LDA, N
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15           COMPLEX       ALPHA, BETA
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17           COMPLEX       A( LDA, * ), X( * ), Y( * )
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PURPOSE

20       CSYMV  performs the matrix-vector  operation
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22       where  alpha  and beta are scalars, x and y are n element vectors and A
23       is an n by n symmetric matrix.
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ARGUMENTS

27       UPLO     (input) CHARACTER*1
28                On entry, UPLO specifies whether the upper or lower triangular
29                part of the array A is to be referenced as follows:
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31                UPLO  = 'U' or 'u'   Only the upper triangular part of A is to
32                be referenced.
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34                UPLO = 'L' or 'l'   Only the lower triangular part of A is  to
35                be referenced.
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37                Unchanged on exit.
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39       N        (input) INTEGER
40                On entry, N specifies the order of the matrix A.  N must be at
41                least zero.  Unchanged on exit.
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43       ALPHA    (input) COMPLEX
44                On entry, ALPHA specifies  the  scalar  alpha.   Unchanged  on
45                exit.
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47       A        (input) COMPLEX array, dimension ( LDA, N )
48                Before  entry,  with   UPLO  =  'U' or 'u', the leading n by n
49                upper triangular part of the array A must  contain  the  upper
50                triangular part of the symmetric matrix and the strictly lower
51                triangular part of A is not referenced.   Before  entry,  with
52                UPLO = 'L' or 'l', the leading n by n lower triangular part of
53                the array A must contain the lower triangular part of the sym‐
54                metric  matrix  and the strictly upper triangular part of A is
55                not referenced.  Unchanged on exit.
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57       LDA      (input) INTEGER
58                On entry, LDA specifies the first dimension of A  as  declared
59                in  the  calling (sub) program. LDA must be at least max( 1, N
60                ).  Unchanged on exit.
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62       X        (input) COMPLEX array, dimension at least
63                ( 1 + ( N - 1 )*abs( INCX ) ).  Before entry, the  incremented
64                array  X  must  contain the N- element vector x.  Unchanged on
65                exit.
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67       INCX     (input) INTEGER
68                On entry, INCX specifies the increment for the elements of  X.
69                INCX must not be zero.  Unchanged on exit.
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71       BETA     (input) COMPLEX
72                On  entry,  BETA  specifies the scalar beta. When BETA is sup‐
73                plied as zero then Y need not be set on input.   Unchanged  on
74                exit.
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76       Y        (input/output) COMPLEX array, dimension at least
77                (  1 + ( N - 1 )*abs( INCY ) ).  Before entry, the incremented
78                array Y must contain the n element vector y.  On  exit,  Y  is
79                overwritten by the updated vector y.
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81       INCY     (input) INTEGER
82                On  entry, INCY specifies the increment for the elements of Y.
83                INCY must not be zero.  Unchanged on exit.
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87 LAPACK auxiliary routine (versionNo3v.e1m)ber 2006                        CSYMV(1)