poisson.h

#pragma once

# include <cstdlib>
# include <iostream>
# include <iomanip>
# include <ctime>
# include <cmath>

using namespace std;

double r8mat_rms ( int m, int n, double **a );
void rhs ( int nx, int ny, double **f );
void sweep ( int nx, int ny, double dx, double dy, double **f, 
  double **u, double **unew);
double u_exact ( double x, double y );
double uxxyy_exact ( double x, double y );