对 -方法导出的几种隐式差分格式编程实现求出数值解；估计数值解的误差界；大致比较几种不同格式的优劣；结合格式的相容性、稳定性和收敛性条件简单分析计算结果-- Export several implicit difference scheme for programming to find the numerical solution　estimated error bounds for the numerical solution　rough comparison of the pros and cons of several different formats　combination of format compatibility, a simple analysis of the stability and convergence conditions The results