Gauss Seidel | Numerik

#include <stdio.h>
#include <math.h>
#include <stdlib.h>
#define maks 100

float A[maks][maks],x[maks], b[maks];
int n;

void tukar_baris(int i, int besar) {
    float temp[100];
    int j;
    for(j=0;j<=n;j++) {
        temp[j] = A[i][j];
        A[i][j] = A[besar][j];
        A[besar][j] = temp[j];
    }
}

void carimatriksb() {
    static int i,j;
    for(i=0;i<n;i++) {
        b[i]=A[i][n];
    }
}

void tampil() {
    int i,j;
    for(i=0;i<n;i++) {
        for(j=0;j<n+1;j++) {
            printf("%3g",A[i][j]);
        }
        printf("\n");
    }
    printf("\n");
}

void masukkan() {
    int i,j;
    float v[100];

    printf(" Masukkan ukuran matriks : "); scanf("%d",&n);
    puts("----------------------------------------");

    for(i=0;i<n;i++) {
        for(j=0;j<n;j++) {
            printf(" matrik A[%d][%d] = ",i+1,j+1);
            scanf("%f",&A[i][j]);
            A[i][j] = A[i][j];
        }
    }

    puts("----------------------------------------");
    printf(" Masukkan vektor matriks : \n");
    puts("----------------------------------------");

    for(i=0;i<j;i++) {
        printf(" vektor [%d] = ",i+1);
        scanf("%f",&v[i]);
        A[i][j] = v[i];
    }

    printf("\n Matriks awal:\n");
    puts("----------------------------------------");
    tampil();
}

void main() {
    int i,j, konvergen, max_iter, iter;
    float smtr, temp, e, ep;
    float xnow[100], xbef[100];

    puts(" METODE ELIMINASI GAUSS SEIDEL");
    puts("========================================");

    masukkan();

    printf(" Jumlah iterasi maksimum : ");
    scanf("%d",&max_iter);
    printf(" Toleransi error         : ");
    scanf("%f",&ep);
    puts("----------------------------------------");
    fflush(stdin);

    carimatriksb();

    for(i=0;i<n;i++) {
        xnow[i] = 0; // nilai awal
    }

    puts("");
    printf("%-5s","iter x1");
        for(i=1;i<n;i++) {
        printf("%10.5s%d","x",i+1);
    }
    for(i=0;i<n;i++) {
        printf("%10.5s","e");
    }

    printf("\n%-5d",0);
    for(i=0;i<n;i++) {
        printf("%-11.5g",xnow[i]);
    }

    printf("\n");
    iter = 1;
    konvergen = 0;

    while(konvergen==0 && iter<max_iter) {
        for(i=0;i<n;i++) {
            temp = 0;
            for(j=0;j<n;j++) {
                if(i != j) {
                    temp = temp + A[i][j] * xnow[j];
                }
            }
            smtr = (b[i] - temp) / A[i][i];
            xbef[i] = xnow[i];
            xnow[i] = smtr;
        }

        printf("%-5d",iter);
        for(i=0;i<n;i++) {
            printf("%-11.5g",xnow[i]);
        }
        for(i=0;i<n;i++) {
            e = fabs(xnow[i] - xbef[i]);
            printf("%-11.5g",e);
            if(i==0 && e<ep) {
                konvergen = 1;
            }
            if(e > 100) {
                printf("hasil divergen\n");
                exit(0);
            }
        }
        printf("\n");
        iter++;
    }

    printf("Hasilnya : \n");
    for(i=0;i<n;i++) {
        printf("x%d : %g\n",i+1,xnow[i]);
    }
}

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