The FORTRAN level-2 BLAS call for this operation is
Here is replaced by S, D, C, or Z to indicate the datatype of the data (single, double, complex, double precision complex). Parameter UPLO indicates whether A is lower (UPLO = "Lower") or upper (UPLO = "Upper") triangular. Parameter N holds the matrix dimension n . Parameter ALPHA holds the scaling factor . Parameters A, X, and Y equal the addresses of where matrix A and vectors x and y start in memory. The leading dimension of the matrix is given in LDA and the stride of the vectors in INCX and INCY.
SUBROUTINE SYR2 ( UPLO, N, ALPHA, X, INCX, Y, INCY, A, LDA )