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LAPACK
3.7.0
LAPACK: Linear Algebra PACKage
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subroutine zsyr | ( | character | UPLO, |
integer | N, | ||
complex*16 | ALPHA, | ||
complex*16, dimension( * ) | X, | ||
integer | INCX, | ||
complex*16, dimension( lda, * ) | A, | ||
integer | LDA | ||
) |
ZSYR performs the symmetric rank-1 update of a complex symmetric matrix.
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ZSYR performs the symmetric rank 1 operation A := alpha*x*x**H + A, where alpha is a complex scalar, x is an n element vector and A is an n by n symmetric matrix.
[in] | 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. Unchanged on exit. |
[in] | N | N is INTEGER On entry, N specifies the order of the matrix A. N must be at least zero. Unchanged on exit. |
[in] | ALPHA | ALPHA is COMPLEX*16 On entry, ALPHA specifies the scalar alpha. Unchanged on exit. |
[in] | 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. Unchanged on exit. |
[in] | INCX | INCX is INTEGER On entry, INCX specifies the increment for the elements of X. INCX must not be zero. Unchanged on exit. |
[in,out] | 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 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. |
[in] | 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 ). Unchanged on exit. |
Definition at line 137 of file zsyr.f.