1ZGEMV(1)                         BLAS routine                         ZGEMV(1)
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NAME

6       ZGEMV - 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 ZGEMV(TRANS,M,N,ALPHA,A,LDA,X,INCX,BETA,Y,INCY)
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13           DOUBLE                                                 COMPLEX
14                                                                  ALPHA,BETA
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16           INTEGER                                                INCX,INCY,LDA,M,N
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18           CHARACTER                                              TRANS
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20           DOUBLE                                                 COMPLEX
21                                                                  A(LDA,*),X(*),Y(*)
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PURPOSE

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

31       TRANS  - CHARACTER*1.
32              On entry, TRANS specifies the operation to be performed as  fol‐
33              lows:
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35              TRANS = 'N' or 'n'   y := alpha*A*x + beta*y.
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37              TRANS = 'T' or 't'   y := alpha*A'*x + beta*y.
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39              TRANS = 'C' or 'c'   y := alpha*conjg( A' )*x + beta*y.
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41              Unchanged on exit.
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43       M      - INTEGER.
44              On  entry,  M  specifies  the number of rows of the matrix A.  M
45              must be at least zero.  Unchanged on exit.
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47       N      - INTEGER.
48              On entry, N specifies the number of columns of the matrix A.   N
49              must be at least zero.  Unchanged on exit.
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51       ALPHA  - COMPLEX*16      .
52              On entry, ALPHA specifies the scalar alpha.  Unchanged on exit.
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54       A      - COMPLEX*16       array of DIMENSION ( LDA, n ).
55              Before  entry,  the leading m by n part of the array A must con‐
56              tain the matrix of coefficients.  Unchanged on exit.
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58       LDA    - INTEGER.
59              On entry, LDA specifies the first dimension of A as declared  in
60              the  calling  (sub)  program.  LDA must be at least max( 1, m ).
61              Unchanged on exit.
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63       X      - COMPLEX*16       array of DIMENSION at least
64              ( 1 + ( n - 1 )*abs( INCX ) ) when TRANS = 'N'  or  'n'  and  at
65              least  (  1  + ( m - 1 )*abs( INCX ) ) otherwise.  Before entry,
66              the incremented array X must contain the vector x.  Unchanged on
67              exit.
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69       INCX   - INTEGER.
70              On  entry,  INCX  specifies the increment for the elements of X.
71              INCX must not be zero.  Unchanged on exit.
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73       BETA   - COMPLEX*16      .
74              On entry, BETA specifies the scalar beta. When BETA is  supplied
75              as zero then Y need not be set on input.  Unchanged on exit.
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77       Y      - COMPLEX*16       array of DIMENSION at least
78              (  1  +  (  m - 1 )*abs( INCY ) ) when TRANS = 'N' or 'n' and at
79              least ( 1 + ( n - 1 )*abs( INCY )  )  otherwise.   Before  entry
80              with  BETA  non-zero,  the  incremented array Y must contain the
81              vector y. On exit, Y is overwritten by the updated vector y.
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83       INCY   - INTEGER.
84              On entry, INCY specifies the increment for the  elements  of  Y.
85              INCY must not be zero.  Unchanged on exit.
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FURTHER DETAILS

88       Level 2 Blas routine.
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90       -- Written on 22-October-1986.
91          Jack Dongarra, Argonne National Lab.
92          Jeremy Du Croz, Nag Central Office.
93          Sven Hammarling, Nag Central Office.
94          Richard Hanson, Sandia National Labs.
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99BLAS routine                     November 2008                        ZGEMV(1)