我正在尝试编写一个函数,以便使用Gauss-Seidel方法求解方程组。到目前为止我的功能不起作用。代码在“输入初始猜测...”之后停止给我输出,并且没有解决我正在输入的功能。这是我的功能或我的代码的其他部分的问题吗?
/* code to solve a nxn system using the Gauss-Seidel method */
#include <stdio.h>
#include <math.h>
#include <stdlib.h>
#define MAX_DIM 100
#define MAX_ITER 500
#define TOLERANCE 1.e-6
void gauss_seidel(double a[][MAX_DIM], double b[], double x[], int n);
void main()
{
int i, j, n;
int violation_counter, answer;
int violation_rows[MAX_DIM];
double sum;
double a[MAX_DIM][MAX_DIM];
double b[MAX_DIM], x[MAX_DIM];
/* read in data */
n = MAX_DIM + 1;
while (n > MAX_DIM) {
printf("Enter the dimension of the system to be solved: ");
scanf_s("%d", &n);
}
printf("\n");
for (i = 0; i < n; i++) {
for (j = 0; j < n; j++) {
printf("Enter a[%d][%d] element of the system matrix: ",i,j);
scanf_s("%lf", &a[i][j]);
}
printf("Enter b[%d] of the right-hand-side vector: ", i);
scanf_s("%lf", &b[i]);
printf("\n");
}
/* test the convergence criterion */
violation_counter = 0;
for (i = 0; i < n; i++) {
sum = 0.0;
for (j = 0; j < n; j++)
if (i != j)
sum = sum + fabs(a[i][j]);
if (fabs(a[i][i]) < sum) {
violation_rows[violation_counter] = i;
violation_counter = violation_counter + 1;
}
if (a[i][i] == 0.0) {
printf("Found diagonal element equal to zero; rearrange equations; exiting ...\n");
exit(0);
}
}
if (violation_counter > 0) {
printf("The Gauss-Seidel convergence criterion is violated in %d rows out of %d\n", violation_counter, n);
printf("Specifically, it was violated in rows:\n");
for (i = 0; i < violation_counter; i++)
printf("%d ", violation_rows[i]);
printf("\n");
printf("Enter 1 if you want to continue; any other number to abort : ");
scanf_s("%d", &answer);
if (answer != 1)
exit(1);
printf("Check results carefully\n\n");
}
/* initialize the solution vector -- initial guesses */
for (i = 0; i < n; i++) {
printf("Enter an initial guess for x[%d] of the solution vector : ",i);
scanf_s("%lf", &x[i]);
}
/* solve the system */
gauss_seidel(a, b, x, n);
/* output solution */
for (i = 0; i < n; i++)
printf("x[%d]=%f\n", i, x[i]);
printf("\n");
}
/* function to solve a system using Gauss-Seidel */
void gauss_seidel(double a[][MAX_DIM], double b[], double x[], int n)
{
double maxerror = 1.0;
double iteration_error;
double e, sum, temp;
int i, j;
while (maxerror > 1.e-6) {
iteration_error = 0.0;
for (i = 0; i < n; i++) {
sum = 0.0;
for (j = 0; j < n; j++) {
if (i != j)
sum = sum + (a[i][j] * x[j]);
}
}
temp = (a[i][n] - sum) / a[i][i];
e = fabs((temp - x[i]) / x[i]);
x[i] = temp;
if (e > iteration_error)
iteration_error = e;
}
maxerror = iteration_error;
}