Abstract
Methods for solving this problem are considered with particular reference to achieving maximum efficiency. A streamlined version of Fletcher's (1971) method for quadratic programming is considered and also a new approach based on the use of partial LDLT factorizations. Results on a wide variety of test problems indicate that the LDLT method is superior in both efficiency and error control. This method can often be expected to solve the problem in a time comparable to that required for a Choleski factorization, and always in a small multiple of this time.