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My Problem In Jacobi Iterative Method

Robertoplusplus (5)
Hi All.I'm Very Very Glad To Join This Lovely Site & Speaking With You.
In This Term At My University I Have Numerical Methods & My Teacher Asks Me To Write 1 Program About Jacobi Iteration Method.I Have Write It But In Iteration Step I Have Problem & So I Want You Help Me To Improve This Or Write Another Iteration.Tnx All...
Here Its My Program :


#include<math.h>
#include<stdio.h>
#include<iostream>
using namespace std;


int sum(int n , int * pn)
{
int sum = 0;

for(int i = 0 ; i<n ; i++)
{sum = sum + pn[i];}

return sum;
}



double Power(double x , int n)
{
int i;
double pow = 1;
for(i = 0 ; i<n ; i++)
{
pow = pow * x ;
}
return pow ;
}


int main()
{
cout<<"Welcome To Robertoplusplus Jacobi Iterative Method Solver\n\n";

int n;
cout<<"Please Enter n:\n";
cin>>n;

cout<<"\n\n";



double ** A;
A = new double * [n];
A[0] = new double [n*n];


for(int i = 0 ; i<n ; i++)
{A[i] = &A[0][n*i];}



for(int i = 0 ; i<n ; i++)
{

for(int j = 0 ; j<n ; j++)
{A[i][j] = Power(((i+1+j+1.)/((2*(i+1)))),j+1);
printf("%lf ",A[i][j]);
}

cout<<endl;

}




double * b;
b = new double [n];


for(int i = 0 ; i<n ; i++)
{

b[i] = Power(i+1,2);
cout<<b[i]<<" ";


cout<<endl;

}

double * x;
x = new double[n];
double * k;
k = new double[n];






for(int j = 0 ; j < n ; j++)
{

cout<<"Please EnTer x["<<j<<"]:\n\n";
cin>>x[j];
}



double * seri;
seri = new double [n];

int * shomareshgar = new int[n];
int y = -2;


while(!(y==n))
{


for(int i = 0 ; i < n ; i++)
{k[i] = x[i];}


for(int i = 0 ; i < n ; i++)
{


for(int j = 0 ; j < n ; j++)
{
seri[i] = 0;


if(!(j == i))
{
seri[i] = seri[i] + A[i][j]*x[i];

}
}

x[i] = (1./A[i][i])*(b[i]-seri[i]);

if(fabs(x[i] - k[i])<1e-10)
{shomareshgar[i] = 1;}
else
{shomareshgar[i] = 0;}

}



for(int i = 0 ; i<n ; i++)
{y = y + shomareshgar[i];}


cout<<"y = "<<y<<endl;
system("pause");



}




cout<<x[0]<<endl;

system("pause");
return 0;
}
CosminNTG (187)
1 - write the code between the [code] tags because I don't understand anything
2 - don't use system("pause") - it will destroy your CPU
3 - what is the problem with the code? what doesn't work?
Robertoplusplus (5)
Tnq U For Notice This.I Retype My Program..My Problem Is In Iteration Step.I Have A Suitable Condition For While Case.
My While In Program Dosent Work Properly.


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include<math.h>
#include<stdio.h>
#include<iostream>
using namespace std;


int sum(int n , int * pn)
{
int sum = 0;

for(int i = 0 ; i<n ; i++)
{sum = sum + pn[i];}

return sum;
}



double Power(double x , int n)
{
int i;
double pow = 1;
for(i = 0 ; i<n ; i++)
{
pow = pow * x ;
}
return pow ;
}


int main()
{
cout<<"Welcome To Robertoplusplus Jacobi Iterative Method Solver\n\n";

int n;
cout<<"Please Enter n:\n";
cin>>n;

cout<<"\n\n";



double ** A;
A = new double * [n];
A[0] = new double [n*n];


for(int i = 0 ; i<n ; i++)
{A[i] = &A[0][n*i];}



for(int i = 0 ; i<n ; i++)
{

for(int j = 0 ; j<n ; j++)
{A[i][j] = Power(((i+1+j+1.)/((2*(i+1)))),j+1);
printf("%lf ",A[i][j]);
}

cout<<endl;

}




double * b;
b = new double [n];


for(int i = 0 ; i<n ; i++)
{

b[i] = Power(i+1,2);
cout<<b[i]<<" ";


cout<<endl;

}

double * x;
x = new double[n];
double * k;
k = new double[n];






for(int j = 0 ; j < n ; j++)
{

cout<<"Please EnTer x["<<j<<"]:\n\n";
cin>>x[j];
}



double * seri;
seri = new double [n];

int * shomareshgar = new int[n];
int y = -2;


while(!(y==n))
{


for(int i = 0 ; i < n ; i++)
{k[i] = x[i];}


for(int i = 0 ; i < n ; i++)
{


for(int j = 0 ; j < n ; j++)
{
seri[i] = 0;


if(!(j == i))
{
seri[i] = seri[i] + A[i][j]*x[i];

}
}

x[i] = (1./A[i][i])*(b[i]-seri[i]);

if(fabs(x[i] - k[i])<1e-10)
{shomareshgar[i] = 1;}
else
{shomareshgar[i] = 0;}

}



for(int i = 0 ; i<n ; i++)
{y = y + shomareshgar[i];}


cout<<"y = "<<y<<endl;
system("pause");



}




cout<<x[0]<<endl;

system("pause);
return 0;
}
Last edited on
Robertoplusplus (5)
I Change My Program But It Doesent Work Yet!Plz Help Me!

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#include<math.h>
#include<stdio.h>
#include<iostream>
using namespace std;


int sum(int n , int * pn)
{
	int sum = 0;

	for(int i = 0 ; i<n ; i++)
		{sum = sum + pn[i];}

	return sum;
	}



double Power(double x , int n)
{
	int i;
	double pow = 1;
	for(i = 0 ; i<n ; i++)
	{
		pow = pow * x ;
	}
	return pow ;
}


int main()
{
	cout<<"Welcome To MY Jacobi Iterative Method Solver\n\n";

	int n;
	cout<<"Please Enter n:\n";
	cin>>n;

	cout<<"\n\n";



	double ** A;
	A = new double * [n];
	A[0] = new double [n*n];


	for(int i = 0 ; i<n ; i++)
	{A[i] = &A[0][n*i];}



	for(int i = 0 ; i<n ; i++)
	{

		for(int j = 0 ; j<n ; j++)
		{A[i][j] = Power(((i+1+j+1.)/((2*(i+1)))),j+1);
		printf("%lf	",A[i][j]);
		}

		cout<<endl;

	}




	double * b;
	b = new double  [n];
	

	for(int i = 0 ; i<n ; i++)
	{

		b[i] = Power(i+1,2);
		cout<<b[i]<<"		";
		

		cout<<endl;

		}

	double * x;
	x = new double[n];
	double * k;
	k = new double[n];

	

	
	

	for(int j = 0 ; j < n ; j++)
	{
		
		cout<<"Please EnTer x["<<j<<"]:\n\n";
		cin>>x[j];
	}

	

		double * seri;
		seri = new double [n];

		int * shomareshgar = new int[n];
		int y = 0;

		
		while(y==0)
		{
			


			for(int i = 0 ; i < n ; i++)
	{
		

		for(int j = 0 ; j < n ; j++)
		{
			seri[i] = 0;
			

			if(!(j == i))
		{
			seri[i] = seri[i] + A[i][j]*x[j];

		}
		}

		x[i] = (1./A[i][i])*(b[i]-seri[i]);;

		
		
			}

			
		for(int i = 0 ; i < n ; i++)
		{cout<<"x["<<i<<"] = "<<x[i]<<endl<<endl;}

		cout<<"For Continue Press 0 ; For Exit Press Any Number :\n\n";
		cin>>y;
			


		
		}
	


		

	system("pause");
	return 0;
}
Last edited on
CosminNTG (187)
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while(y==0)
{
			
	for(int i = 0 ; i < n ; i++)
	{
		
  
		for(int j = 0 ; j < n ; j++)
		{
			seri[i] = 0;
			

			if(!(j == i))
		           seri[i] = seri[i] + A[i][j]*x[j];

		        
		}

		x[i] = (1./A[i][i])*(b[i]-seri[i]);;

		
		
	}

			
	for(int i = 0 ; i < n ; i++)
	{cout<<"x["<<i<<"] = "<<x[i]<<endl<<endl;}

	cout<<"For Continue Press 0 ; For Exit Press Any Number :\n\n";
	cin>>y;
			
}

This is your loop. Try to run it in another new project and you'll see what's wrong. I didn't run it but I can say that this loop is working properly because your condition implies a variable that is manipulated in that loop so the condition can be false. Your problem is not in that loop.
Robertoplusplus (5)
Thanks A Lot My Dear..But Do U Have Idea For A New Loop Can Does Iteration Proper?
CosminNTG (187)
Can you be more exact? I don't really understand what are you saying in your last post.
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