1CGEMV(1)                         BLAS routine                         CGEMV(1)
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NAME

6       CGEMV - performs one of the matrix-vector operations   y := alpha*A*x +
7       beta*y, or y := alpha*A'*x + beta*y, or   y := alpha*conjg(  A'  )*x  +
8       beta*y,
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SYNOPSIS

11       SUBROUTINE CGEMV(TRANS,M,N,ALPHA,A,LDA,X,INCX,BETA,Y,INCY)
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13           COMPLEX                                                ALPHA,BETA
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15           INTEGER                                                INCX,INCY,LDA,M,N
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17           CHARACTER                                              TRANS
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19           COMPLEX                                                A(LDA,*),X(*),Y(*)
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PURPOSE

22       CGEMV performs one of the matrix-vector operations
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24       where  alpha and beta are scalars, x and y are vectors and A is an m by
25       n matrix.
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ARGUMENTS

29       TRANS  - CHARACTER*1.
30              On entry, TRANS specifies the operation to be performed as  fol‐
31              lows:
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33              TRANS = 'N' or 'n'   y := alpha*A*x + beta*y.
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35              TRANS = 'T' or 't'   y := alpha*A'*x + beta*y.
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37              TRANS = 'C' or 'c'   y := alpha*conjg( A' )*x + beta*y.
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39              Unchanged on exit.
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41       M      - INTEGER.
42              On  entry,  M  specifies  the number of rows of the matrix A.  M
43              must be at least zero.  Unchanged on exit.
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45       N      - INTEGER.
46              On entry, N specifies the number of columns of the matrix A.   N
47              must be at least zero.  Unchanged on exit.
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49       ALPHA  - COMPLEX         .
50              On entry, ALPHA specifies the scalar alpha.  Unchanged on exit.
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52       A      - COMPLEX          array of DIMENSION ( LDA, n ).
53              Before  entry,  the leading m by n part of the array A must con‐
54              tain the matrix of coefficients.  Unchanged on exit.
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56       LDA    - INTEGER.
57              On entry, LDA specifies the first dimension of A as declared  in
58              the  calling  (sub)  program.  LDA must be at least max( 1, m ).
59              Unchanged on exit.
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61       X      - COMPLEX          array of DIMENSION at least
62              ( 1 + ( n - 1 )*abs( INCX ) ) when TRANS = 'N'  or  'n'  and  at
63              least  (  1  + ( m - 1 )*abs( INCX ) ) otherwise.  Before entry,
64              the incremented array X must contain the vector x.  Unchanged on
65              exit.
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67       INCX   - 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   - COMPLEX         .
72              On entry, BETA specifies the scalar beta. When BETA is  supplied
73              as zero then Y need not be set on input.  Unchanged on exit.
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75       Y      - COMPLEX          array of DIMENSION at least
76              (  1  +  (  m - 1 )*abs( INCY ) ) when TRANS = 'N' or 'n' and at
77              least ( 1 + ( n - 1 )*abs( INCY )  )  otherwise.   Before  entry
78              with  BETA  non-zero,  the  incremented array Y must contain the
79              vector y. On exit, Y is overwritten by the updated vector y.
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81       INCY   - 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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FURTHER DETAILS

86       Level 2 Blas routine.
87
88       -- Written on 22-October-1986.
89          Jack Dongarra, Argonne National Lab.
90          Jeremy Du Croz, Nag Central Office.
91          Sven Hammarling, Nag Central Office.
92          Richard Hanson, Sandia National Labs.
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97BLAS routine                     November 2008                        CGEMV(1)