A class of novel deferred correction methods, integral deferred correction
(IDC) methods, is studied. This class of methods is an extension of ideas
introduced by Dutt, Greengard and Rokhlin on spectral deferred correction
(SDC) methods for solving ordinary differential equations (ODEs). The
novel nature of this class of defect correction methods is that the correction
of the defect is carried out using an accurate integral form of the residual
instead of the more familiar differential form. As a family of methods, these
schemes are capable of matching the efficiency of popular high-order RK
methods.
The smoothness of the error vector associated with an IDC method is an important
indicator of the order of convergence that can be expected from a scheme (Christlieb,
Ong, and Qiu; Hansen and Strain; Skeel). It is demonstrated that embedding an
-th
order integrator in the correction loop of an IDC method does not always result in an
-th
order increase in accuracy. Examples include IDC methods constructed using
non-self-starting multistep integrators, and IDC methods constructed using a
nonuniform distribution of quadrature nodes.
Additionally, the integral deferred correction concept is reposed as a framework to
generate high-order Runge–Kutta (RK) methods; specifically, we explain how the
prediction and correction loops can be incorporated as stages of a high-order RK
method. This alternate point of view allows us to utilize standard methods for
quantifying the performance (efficiency, accuracy and stability) of integral
deferred correction schemes. It is found that IDC schemes constructed using
uniformly distributed nodes and high-order integrators are competitive in
terms of efficiency with IDC schemes constructed using Gauss–Lobatto nodes
and forward Euler integrators. With respect to regions of absolute stability,
however, IDC methods constructed with uniformly distributed nodes and
high-order integrators are far superior. It is observed that as the order of
the embedded integrator increases, the stability region of the IDC method
increases.