Figure 4. Amplification factor diagram for the thin semi-infinite 

 breakwater for incident wave angle = deg 



and III (as defined in Figure 2) where the reflected wave is absent, the am- 

 plification factor is essentially the diffraction coefficient as defined in 

 the SPM. 



26. Figures 4 through 15 reveal that the amplification factors in sub- 

 region I change very rapidly between and 2.35 over the subregion, and the 

 diagram patterns become very complex because of the interesting superposition 

 of the incident, reflected, and scattered waves. (In the legend of Figures 4 

 through 15, the width of the pixel is one incident wave length, and the values 

 are amplification factors.) Such patterns would be very difficult to con- 

 struct without using a high-speed computer and computer graphics. In sub- 

 regions II and III, the amplification factors change smoothly from 1.15 

 roughly along the reflected wave ray reflected from the origin point to nearly 



15 



