| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To solve a problem that when a numerical solution includes a comparatively high frequency component and a comparatively low frequency component in the case of finding out the numerical solution of a differential equation by a difference method such as a trapezoid formula, section division should be set to a sufficiently small value as compared with a short period (wavelength) of a high frequency component and therefore extremely large calculation load is required for finding out solutions of a large (wide) area in which a low frequency component is concerned. <P>SOLUTION: As a means for solving problems in a conventional method for solving a differential equation, an area is divided into a plurality of sections and an unknown variable is approximated by (discrete) Fourier series in the sections. Then the differential equation is transformed into a difference equation between coefficients of the (discrete) Fourier series of the unknown variable and the difference equation is solved to numerically solve the differential equation. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
