advection.cpp

偏微分方程数值解- 这是矩阵的紧致存储及在紧致存储的矩阵上用共轭梯度(CG)方法解Poisson方程的实现, gcc mingw 3.4.4下通过

#include <math.h>
#include <iostream.h>

double FB(int t, int x, double c){
	if(x==0) return 1;
	else if(t==0) return 0;
	else return (FB(t-1,x,c)-c*(FB(t-1,x,c)-FB(t-1,x-1,c)));
}

double BB(int t, int x, double c){
	if(x==0) return 1;
	else if(t==0) return 0;
	else return (1.0/(1+c)*(BB(t-1,x,c)+c*BB(t,x-1,c)));
}

int main(void){
	cout<<"C=0.5 for FB: u(5,x) is ";
	for(int i=1;i<10;i++)
		cout<<FB(5,i,0.5)<<",  ";
	cout<<endl<<"C=1 for FB: u(5,x) is ";
	for(int i=1;i<10;i++)
		cout<<FB(5,i,1)<<",  ";
	cout<<endl<<"C=2 for FB: u(5,x) is ";
	for(int i=1;i<10;i++)
		cout<<FB(5,i,2)<<",  ";
	cout<<endl<<"C=2 for BB: u(5,x) is ";
	for(int i=1;i<10;i++)
		cout<<BB(5,i,2)<<",  ";








	getchar();
}