DAXPY(3) MathKeisan BLAS routine DAXPY(3)NAMEDAXPY - BLAS level one axpy subroutineSYNOPSISSUBROUTINE DAXPY ( n, alpha, x, incx, y, incy ) INTEGER n, incx, incy DOUBLE PRECISION alpha, x, yDESCRIPTIONDAXPY adds a scalar multiple of a double precision vector to another double precision vector. DAXPY computes a constant alpha times a vector x plus a vector y. The result overwrites the initial values of vector y. This routine performs the following vector operation: y <-- alpha*x + y incx and incy specify the increment between two consecutive elements of respectively vector x and y.ARGUMENTSn INTEGER. (input) Number of elements in the vectors. If n <= 0, these routines return without any computation. alpha DOUBLE PRECISION. (input) If alpha = 0 this routine returns without any computation. x DOUBLE PRECISION, (input) Array of dimension (n-1) * |incx| + 1. Contains the vector to be scaled before summation. incx INTEGER. (input) Increment between elements of x. If incx = 0, the results will be unpredictable. y DOUBLE PRECISION, (input and output) array of dimension (n-1) * |incy| + 1. Before calling the routine, y contains the vector to be summed. After the routine ends, y contains the result of the summation. incy INTEGER. (input) Increment between elements of y. If incy = 0, the results will be unpredictable.NOTESThis routine is Level 1 Basic Linear Algebra Subprograms (Level 1 BLAS). When working backward (incx < 0 or incy < 0), each routine starts at the end of the vector and moves backward, as follows: x(1-incx * (n-1)), x(1-incx * (n-2)), ..., x(1) y(1-incy * (n-1)), y(1-incy * (n-2)), ..., y(1)RETURN VALUESWhen n <= 0, double precision alpha = 0., this routine returns immedi- ately with no change in its arguments. MathKeisan DAXPY(3)