programming-examples/c++/Computational_Geometry/C++ Program to Implement GAUSS SIEDEL ITERATION METHOD TO SOLVE LINEAR EQUATIONS.cpp
2019-11-15 12:59:38 +01:00

80 lines
2.7 KiB
C++

/*------- GAUSS SIEDEL ITERATION METHOD TO SOLVE LINEAR EQUATIONS -----*/
/* THE PROGRAM SOLVES THE SYSTEM OF LINEAR EQUATIONS USING
GAUSS SIEDEL ITERATION METHOD.
INPUTS : 1) Number of variables in the equation.
2) Coefficient's of linear equations.
OUTPUTS : Results of every iteration till 'q' is pressed. */
/*------------------------------ PROGRAM --------------------------*/
#include<stdio.h>
#include<math.h>
#include<stdlib.h>
#include<conio.h>
void main()
{
double a[10][10],x[10],y[10];
/* ARRAY OF a[n][n] STORING COEFFICIENTS OF EQUATIONS */
int i,j,n;
char ch;
clrscr();
printf("\n GAUSS SIEDEL METHOD TO SOLVE LINEAR EQUATIONS");
printf("\n\n The form of equations is as follows\n\n"
" a11x1 + a12x2 + ... + a1nxn = b1\n"
" a21x1 + a22x2 + ... + a2nxn = b2\n"
" a31x1 + a32x2 + ... + a3nxn = b3\n"
" ................................\n"
" an1x1 + an2x2 + ... + annxn = bn\n");
printf("\n\nEnter the number of variables (max 10) = ");
/* ENTER THE NUMBER OF VARIABLES IN THE EQUATION */
scanf("%d",&n);
for(i = 1; i <= n; i++)
{
/* LOOP TO GET COEFFICIENTS a11,a12...,ann & so on */
for(j = 1; j <= n; j++)
{
printf("a%d%d = ",i,j);
scanf("%lf",&a[i][j]);
}
printf("b%d = ",i);
scanf("%lf",&a[i][j]);
x[i] = y[i] = 0;
}
printf("\n\nThe results are as follows....\n\n"
"press 'enter' key to continue iterations &"
" press 'q' to stop iterations....\n\n");
while(ch != 'q')
{
for(i = 1; i <= n; i++)
{
/* LOOP TO CALCULATE VALUES OF x1,x2,...,xn etc */
for(j = 1; j <= n; j++)
{
if(i == j) continue;
x[i] = x[i] - a[i][j]*y[j];
}
x[i] = x[i] + a[i][j];
x[i] = x[i]/a[i][i];
y[i] = x[i]; /* TAKE VALUES FROM CURRENT ITERATIONS */
}
for(i = 1; i <= n; i++)
{
/* LOOP TO PRINT VALUES OF x1,x2,...xn etc */
y[i] = x[i];
printf("x%d = %lf ",i,x[i]);
x[i] = 0;
}
ch = getch();
printf("\n\n");
}
}
/*-------------------------------- END OF PROGRAM ---------------------*/