A preconditioned conjugate gradient frontal solver for three dimensional electromagnetic field problems

A new method is given for solving the large sparse system of linear algebraic equations Ax = b which arises in three-dimensional finite element problems. It combines incomplete frontal factorization with the preconditioned conjugate gradient technique. The resulting hybrid method makes large three-dimensional problems feasible even with limited computer memory, since it automatically trades memory for execution time. Thus as problems become larger computing times increase dramatically but solution is still possible.