improved1.c

国外一大学教授讲章

/* Improved bare-bones 1D FDTD simulation. */

#include "fdtd1.h"
#include <math.h>

int main()
{
  Grid g;                                   
  double imp0=377.0; 
  int mm;

  SizeX   = 200;  // size of grid           
  MaxTime = 250;  // duration of simulation 
  Cdtds   = 1.0;  // Courant number (unused)

  ALLOC_1D(g.ez, SizeX, double);            
  ALLOC_1D(g.hy, SizeX, double);            

  /* do time stepping */
  for (Time=0; Time<MaxTime; Time++) { 

    /* update magnetic field */
    for (mm=0; mm<SizeX-1; mm++)           
      Hy(mm) = Hy(mm) + (Ez(mm+1) - Ez(mm))/imp0;

    /* update electric field */
    for (mm=1; mm<SizeX; mm++)             
      Ez(mm) = Ez(mm) + (Hy(mm) - Hy(mm-1))*imp0;

    /* hardwire a source node */
    Ez(0) = exp(-(Time-30.)*(Time-30.)/100.);

    printf("%g\n",Ez(50));
  } /* end of time-stepping */

  return 0;
}