Provided by: liblapack-doc_3.12.0-3build1.1_all bug

NAME

       her2 - {he,sy}r2: Hermitian/symmetric rank-2 update

SYNOPSIS

   Functions
       subroutine cher2 (uplo, n, alpha, x, incx, y, incy, a, lda)
           CHER2
       subroutine dsyr2 (uplo, n, alpha, x, incx, y, incy, a, lda)
           DSYR2
       subroutine ssyr2 (uplo, n, alpha, x, incx, y, incy, a, lda)
           SSYR2
       subroutine zher2 (uplo, n, alpha, x, incx, y, incy, a, lda)
           ZHER2

Detailed Description

Function Documentation

   subroutine cher2 (character uplo, integer n, complex alpha, complex, dimension(*) x, integer
       incx, complex, dimension(*) y, integer incy, complex, dimension(lda,*) a, integer lda)
       CHER2

       Purpose:

            CHER2  performs the hermitian rank 2 operation

               A := alpha*x*y**H + conjg( alpha )*y*x**H + A,

            where alpha is a scalar, x and y are n element vectors and A is an n
            by n hermitian matrix.

       Parameters
           UPLO

                     UPLO is CHARACTER*1
                      On entry, UPLO specifies whether the upper or lower
                      triangular part of the array A is to be referenced as
                      follows:

                         UPLO = 'U' or 'u'   Only the upper triangular part of A
                                             is to be referenced.

                         UPLO = 'L' or 'l'   Only the lower triangular part of A
                                             is to be referenced.

           N

                     N is INTEGER
                      On entry, N specifies the order of the matrix A.
                      N must be at least zero.

           ALPHA

                     ALPHA is COMPLEX
                      On entry, ALPHA specifies the scalar alpha.

           X

                     X is COMPLEX array, dimension at least
                      ( 1 + ( n - 1 )*abs( INCX ) ).
                      Before entry, the incremented array X must contain the n
                      element vector x.

           INCX

                     INCX is INTEGER
                      On entry, INCX specifies the increment for the elements of
                      X. INCX must not be zero.

           Y

                     Y is COMPLEX array, dimension at least
                      ( 1 + ( n - 1 )*abs( INCY ) ).
                      Before entry, the incremented array Y must contain the n
                      element vector y.

           INCY

                     INCY is INTEGER
                      On entry, INCY specifies the increment for the elements of
                      Y. INCY must not be zero.

           A

                     A is COMPLEX array, dimension ( LDA, N )
                      Before entry with  UPLO = 'U' or 'u', the leading n by n
                      upper triangular part of the array A must contain the upper
                      triangular part of the hermitian matrix and the strictly
                      lower triangular part of A is not referenced. On exit, the
                      upper triangular part of the array A is overwritten by the
                      upper triangular part of the updated matrix.
                      Before entry with UPLO = 'L' or 'l', the leading n by n
                      lower triangular part of the array A must contain the lower
                      triangular part of the hermitian matrix and the strictly
                      upper triangular part of A is not referenced. On exit, the
                      lower triangular part of the array A is overwritten by the
                      lower triangular part of the updated matrix.
                      Note that the imaginary parts of the diagonal elements need
                      not be set, they are assumed to be zero, and on exit they
                      are set to zero.

           LDA

                     LDA is INTEGER
                      On entry, LDA specifies the first dimension of A as declared
                      in the calling (sub) program. LDA must be at least
                      max( 1, n ).

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Further Details:

             Level 2 Blas routine.

             -- Written on 22-October-1986.
                Jack Dongarra, Argonne National Lab.
                Jeremy Du Croz, Nag Central Office.
                Sven Hammarling, Nag Central Office.
                Richard Hanson, Sandia National Labs.

   subroutine dsyr2 (character uplo, integer n, double precision alpha, double precision,
       dimension(*) x, integer incx, double precision, dimension(*) y, integer incy, double
       precision, dimension(lda,*) a, integer lda)
       DSYR2

       Purpose:

            DSYR2  performs the symmetric rank 2 operation

               A := alpha*x*y**T + alpha*y*x**T + A,

            where alpha is a scalar, x and y are n element vectors and A is an n
            by n symmetric matrix.

       Parameters
           UPLO

                     UPLO is CHARACTER*1
                      On entry, UPLO specifies whether the upper or lower
                      triangular part of the array A is to be referenced as
                      follows:

                         UPLO = 'U' or 'u'   Only the upper triangular part of A
                                             is to be referenced.

                         UPLO = 'L' or 'l'   Only the lower triangular part of A
                                             is to be referenced.

           N

                     N is INTEGER
                      On entry, N specifies the order of the matrix A.
                      N must be at least zero.

           ALPHA

                     ALPHA is DOUBLE PRECISION.
                      On entry, ALPHA specifies the scalar alpha.

           X

                     X is DOUBLE PRECISION array, dimension at least
                      ( 1 + ( n - 1 )*abs( INCX ) ).
                      Before entry, the incremented array X must contain the n
                      element vector x.

           INCX

                     INCX is INTEGER
                      On entry, INCX specifies the increment for the elements of
                      X. INCX must not be zero.

           Y

                     Y is DOUBLE PRECISION array, dimension at least
                      ( 1 + ( n - 1 )*abs( INCY ) ).
                      Before entry, the incremented array Y must contain the n
                      element vector y.

           INCY

                     INCY is INTEGER
                      On entry, INCY specifies the increment for the elements of
                      Y. INCY must not be zero.

           A

                     A is DOUBLE PRECISION array, dimension ( LDA, N )
                      Before entry with  UPLO = 'U' or 'u', the leading n by n
                      upper triangular part of the array A must contain the upper
                      triangular part of the symmetric matrix and the strictly
                      lower triangular part of A is not referenced. On exit, the
                      upper triangular part of the array A is overwritten by the
                      upper triangular part of the updated matrix.
                      Before entry with UPLO = 'L' or 'l', the leading n by n
                      lower triangular part of the array A must contain the lower
                      triangular part of the symmetric matrix and the strictly
                      upper triangular part of A is not referenced. On exit, the
                      lower triangular part of the array A is overwritten by the
                      lower triangular part of the updated matrix.

           LDA

                     LDA is INTEGER
                      On entry, LDA specifies the first dimension of A as declared
                      in the calling (sub) program. LDA must be at least
                      max( 1, n ).

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Further Details:

             Level 2 Blas routine.

             -- Written on 22-October-1986.
                Jack Dongarra, Argonne National Lab.
                Jeremy Du Croz, Nag Central Office.
                Sven Hammarling, Nag Central Office.
                Richard Hanson, Sandia National Labs.

   subroutine ssyr2 (character uplo, integer n, real alpha, real, dimension(*) x, integer incx,
       real, dimension(*) y, integer incy, real, dimension(lda,*) a, integer lda)
       SSYR2

       Purpose:

            SSYR2  performs the symmetric rank 2 operation

               A := alpha*x*y**T + alpha*y*x**T + A,

            where alpha is a scalar, x and y are n element vectors and A is an n
            by n symmetric matrix.

       Parameters
           UPLO

                     UPLO is CHARACTER*1
                      On entry, UPLO specifies whether the upper or lower
                      triangular part of the array A is to be referenced as
                      follows:

                         UPLO = 'U' or 'u'   Only the upper triangular part of A
                                             is to be referenced.

                         UPLO = 'L' or 'l'   Only the lower triangular part of A
                                             is to be referenced.

           N

                     N is INTEGER
                      On entry, N specifies the order of the matrix A.
                      N must be at least zero.

           ALPHA

                     ALPHA is REAL
                      On entry, ALPHA specifies the scalar alpha.

           X

                     X is REAL array, dimension at least
                      ( 1 + ( n - 1 )*abs( INCX ) ).
                      Before entry, the incremented array X must contain the n
                      element vector x.

           INCX

                     INCX is INTEGER
                      On entry, INCX specifies the increment for the elements of
                      X. INCX must not be zero.

           Y

                     Y is REAL array, dimension at least
                      ( 1 + ( n - 1 )*abs( INCY ) ).
                      Before entry, the incremented array Y must contain the n
                      element vector y.

           INCY

                     INCY is INTEGER
                      On entry, INCY specifies the increment for the elements of
                      Y. INCY must not be zero.

           A

                     A is REAL array, dimension ( LDA, N )
                      Before entry with  UPLO = 'U' or 'u', the leading n by n
                      upper triangular part of the array A must contain the upper
                      triangular part of the symmetric matrix and the strictly
                      lower triangular part of A is not referenced. On exit, the
                      upper triangular part of the array A is overwritten by the
                      upper triangular part of the updated matrix.
                      Before entry with UPLO = 'L' or 'l', the leading n by n
                      lower triangular part of the array A must contain the lower
                      triangular part of the symmetric matrix and the strictly
                      upper triangular part of A is not referenced. On exit, the
                      lower triangular part of the array A is overwritten by the
                      lower triangular part of the updated matrix.

           LDA

                     LDA is INTEGER
                      On entry, LDA specifies the first dimension of A as declared
                      in the calling (sub) program. LDA must be at least
                      max( 1, n ).

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Further Details:

             Level 2 Blas routine.

             -- Written on 22-October-1986.
                Jack Dongarra, Argonne National Lab.
                Jeremy Du Croz, Nag Central Office.
                Sven Hammarling, Nag Central Office.
                Richard Hanson, Sandia National Labs.

   subroutine zher2 (character uplo, integer n, complex*16 alpha, complex*16, dimension(*) x,
       integer incx, complex*16, dimension(*) y, integer incy, complex*16, dimension(lda,*) a,
       integer lda)
       ZHER2

       Purpose:

            ZHER2  performs the hermitian rank 2 operation

               A := alpha*x*y**H + conjg( alpha )*y*x**H + A,

            where alpha is a scalar, x and y are n element vectors and A is an n
            by n hermitian matrix.

       Parameters
           UPLO

                     UPLO is CHARACTER*1
                      On entry, UPLO specifies whether the upper or lower
                      triangular part of the array A is to be referenced as
                      follows:

                         UPLO = 'U' or 'u'   Only the upper triangular part of A
                                             is to be referenced.

                         UPLO = 'L' or 'l'   Only the lower triangular part of A
                                             is to be referenced.

           N

                     N is INTEGER
                      On entry, N specifies the order of the matrix A.
                      N must be at least zero.

           ALPHA

                     ALPHA is COMPLEX*16
                      On entry, ALPHA specifies the scalar alpha.

           X

                     X is COMPLEX*16 array, dimension at least
                      ( 1 + ( n - 1 )*abs( INCX ) ).
                      Before entry, the incremented array X must contain the n
                      element vector x.

           INCX

                     INCX is INTEGER
                      On entry, INCX specifies the increment for the elements of
                      X. INCX must not be zero.

           Y

                     Y is COMPLEX*16 array, dimension at least
                      ( 1 + ( n - 1 )*abs( INCY ) ).
                      Before entry, the incremented array Y must contain the n
                      element vector y.

           INCY

                     INCY is INTEGER
                      On entry, INCY specifies the increment for the elements of
                      Y. INCY must not be zero.

           A

                     A is COMPLEX*16 array, dimension ( LDA, N )
                      Before entry with  UPLO = 'U' or 'u', the leading n by n
                      upper triangular part of the array A must contain the upper
                      triangular part of the hermitian matrix and the strictly
                      lower triangular part of A is not referenced. On exit, the
                      upper triangular part of the array A is overwritten by the
                      upper triangular part of the updated matrix.
                      Before entry with UPLO = 'L' or 'l', the leading n by n
                      lower triangular part of the array A must contain the lower
                      triangular part of the hermitian matrix and the strictly
                      upper triangular part of A is not referenced. On exit, the
                      lower triangular part of the array A is overwritten by the
                      lower triangular part of the updated matrix.
                      Note that the imaginary parts of the diagonal elements need
                      not be set, they are assumed to be zero, and on exit they
                      are set to zero.

           LDA

                     LDA is INTEGER
                      On entry, LDA specifies the first dimension of A as declared
                      in the calling (sub) program. LDA must be at least
                      max( 1, n ).

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Further Details:

             Level 2 Blas routine.

             -- Written on 22-October-1986.
                Jack Dongarra, Argonne National Lab.
                Jeremy Du Croz, Nag Central Office.
                Sven Hammarling, Nag Central Office.
                Richard Hanson, Sandia National Labs.

Author

       Generated automatically by Doxygen for LAPACK from the source code.