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Calculates the rank–2 update of the upper or lower triangular component of a symmetric matrix.

Details  

	x is an N-element real vector.
	y is an N-element real vector.
	A is a real symmetric matrix of at least N rows and N columns. The VI updates either the upper or lower triangular component of A, depending on what you select for matrix A type. The default is an N × N matrix with all elements equal to 0.
	matrix A type specifies whether to update the upper or lower triangular component of A. 2 Lower Triangular—The VI uses only the lower triangular component of A to calculate the update. 3 Upper Triangular (default)—The VI uses only the upper triangular component of A to calculate the update.
	alpha is the real scale factor for x*y^T and y*x^T, where x^T is the same as x transposed. The default is 1.
	dsyr2 is a real matrix of the same dimensions as A. For the elements in the first N rows and N columns of the triangular component you select for matrix A type, dsyr2 returns the results of the calculation. For any remaining elements, dsyr2 returns the value of the element in A with the same index.
	error returns any error or warning from the VI. You can wire error to the Error Cluster From Error Code VI to convert the error code or warning into an error cluster.

dsyr2 - Symmetric Matrix Rank-2 Update (DBL) Details

Refer to BLAS (Basic Linear Algebra Subprograms) for more information on the BLAS functions.