Patent Document ID: 7856466
Application ID: 11300494
Patent Flag: 1

Claim One:
1. An information processing apparatus comprising: a central processing unit operatively connected to the information processing apparatus, wherein the central processing unit comprises: a first calculating unit configured to perform calculations based on a conjugate gradient method or a method derived therefrom; a determining unit configured to determine, based on resulting data of a cumulative decreased amount CRD t and a cumulative increased amount CRI t obtained each time the first calculating unit iterates the calculations, where CRD t =CRD t-1 + max [(R o -R t ), 0], CRI t =CRI t-1 + max [(R t -R MIN ), 0], t is an iteration count, R is a residual value, whether the calculations diverge when εCRD t <CRI t where εis a real positive number; and a second calculating unit configured to perform calculations based on a conjugate residual method or a method derived therefrom, wherein the central processing unit terminates iteration of the calculations by the first calculating unit and initiates the calculations by the second calculating unit, if the determining unit determines that the calculations performed by the first calculating unit diverge.