Numerical Evolution of axisymmetric vacuum spacetimes: a code based on   the Galerkin method
  We present the first numerical code based on the Galerkin and Collocation methods to integrate the field equations of the Bondi problem. The Galerkin method like all spectral methods provide high accuracy with moderate computational effort. Several numerical tests were performed to verify the issues of convergence, stability and accuracy with promising results. This code opens up several possibilities of applications in more general scenarios for studying the evolution of spacetimes with gravitational waves. 
H. P. de Oliveira and E. L. Rodrigues