1ZHER(1)                          BLAS routine                          ZHER(1)
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NAME

6       ZHER - the hermitian rank 1 operation   A := alpha*x*conjg( x' ) + A,
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SYNOPSIS

9       SUBROUTINE ZHER(UPLO,N,ALPHA,X,INCX,A,LDA)
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11           DOUBLE                                 PRECISION ALPHA
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13           INTEGER                                INCX,LDA,N
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15           CHARACTER                              UPLO
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17           DOUBLE                                 COMPLEX A(LDA,*),X(*)
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PURPOSE

20       ZHER   performs the hermitian rank 1 operation
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22       where alpha is a real scalar, x is an n element vector and A is an n by
23       n hermitian matrix.
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ARGUMENTS

27       UPLO   - 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 be
32              referenced.
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34              UPLO = 'L' or 'l'   Only the lower triangular part of A is to be
35              referenced.
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37              Unchanged on exit.
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39       N      - 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  - DOUBLE PRECISION.
44              On entry, ALPHA specifies the scalar alpha.  Unchanged on exit.
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46       X      - COMPLEX*16       array of dimension at least
47              ( 1 + ( n - 1 )*abs( INCX ) ).  Before  entry,  the  incremented
48              array X must contain the n element vector x.  Unchanged on exit.
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50       INCX   - INTEGER.
51              On  entry,  INCX  specifies the increment for the elements of X.
52              INCX must not be zero.  Unchanged on exit.
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54       A      - COMPLEX*16       array of DIMENSION ( LDA, n ).
55              Before entry with  UPLO = 'U' or 'u', the leading n by  n  upper
56              triangular part of the array A must contain the upper triangular
57              part of the hermitian matrix and the strictly  lower  triangular
58              part  of A is not referenced. On exit, the upper triangular part
59              of the array A is overwritten by the upper  triangular  part  of
60              the  updated  matrix.   Before entry with UPLO = 'L' or 'l', the
61              leading n by n lower triangular part of the array A must contain
62              the  lower  triangular  part  of  the  hermitian  matrix and the
63              strictly upper triangular part of A is not referenced. On  exit,
64              the  lower  triangular part of the array A is overwritten by the
65              lower triangular part of the  updated  matrix.   Note  that  the
66              imaginary  parts  of the diagonal elements need not be set, they
67              are assumed to be zero, and on exit they are set to zero.
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69       LDA    - INTEGER.
70              On entry, LDA specifies the first dimension of A as declared  in
71              the  calling  (sub)  program.  LDA must be at least max( 1, n ).
72              Unchanged on exit.
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74              Level 2 Blas routine.
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76              -- Written on 22-October-1986.  Jack Dongarra, Argonne  National
77              Lab.   Jeremy Du Croz, Nag Central Office.  Sven Hammarling, Nag
78              Central Office.  Richard Hanson, Sandia National Labs.
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82BLAS routine                     November 2006                         ZHER(1)
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