Solitary Wave Solutions of KP equation, Cylindrical KP Equation and Spherical KP Equation

Three (2+ 1)-dimensional equations-KP equation, cylindrical KP equation and spherical KP equation, have been reduced to the same KdV equation by different transformation of variables respectively. Since the single solitary wave solution and 2-solitary wave solution of the KdV equation have been known already, substituting the solutions of the KdV equation into the corresponding transformation of variables respectively, the single and 2-solitary wave solutions of the three (2+ 1)-dimensional equations can be obtained successfully.