938167.fig.0014a
(a)
938167.fig.0014b
(b)
Figure 14: The exterior Dirichlet problem for Helmholtz equation with RCIP applied to (55). The program demo11.m is used with as in (1), and . The boundary condition of (51) is generated by a point source at . (a) The absolute error in at . (b) The number of GMRES iterations needed to meet an estimated relative residual of .