TABLE OF CONTENTS Most of the time spent in "computer" simulation is actually "human" time devoted to programming, translating the differential equation structure of physics to the finite-difference structure of computation, and finally, to analyzing and understanding the results. Simply implementing double-precision arithmetic on an unfamiliar system, or learning to use yet another graphics package for generating postscript plots, are recurring time sinks. This necessary time can be reduced by dividing the programming task into parts and checking the individual parts before they are combined. This division has the fringe benefit that the parts can often be reused in developing other computer programs. Computational checks should first be performed on the smallest feasible problems. Debugging tools are very useful for finding errors in larger problems. Graphics (or "visualization") software makes it possible to plot field variables and contours and to produce animations. Parallel computing provides an opportunity to run longer, larger problems.
