text: #include <stdio.h>
  #include "timestep.h"
  #define NCELLS 10000000
  static double H[NCELLS], U[NCELLS], V[NCELLS], dx[NCELLS], dy[NCELLS];
  static int celltype[NCELLS];
  
  int main(int argc, char *argv[]){
     double g = 9.80, sigma = 0.95;
     double mymindt;
     for (int ic=0; ic<NCELLS ; ic++) {
        H[ic] = 10.0;
        U[ic] = 0.0;
        V[ic] = 0.0;
        dx[ic] = 0.5;
        dy[ic] = 0.5;
        celltype[ic] = REAL_CELL;
     }
     H[NCELLS/2] = 20.0;
  
     mymindt = timestep(NCELLS, g, sigma, celltype, H, U, V, dx, dy);
  
     printf("Minimum dt is %lf\n",mymindt);
  }
  
  