Gauss Jordan | Numerik

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

float A[maks][maks];
float ep;
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 tampil()
{
    int i,j;
    for(i=0;i<n;i++) {
        for(j=0;j<n+1;j++) {
            printf("%5g",A[i][j]);
        }
        printf("\n");
    }
    printf("\n");
}

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

    printf(" Masukkan toleransi error : "); scanf("%d", &ep);

    fflush(stdin);
    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];
    }

    /* pengecekan tukar baris */
    for(i=0;i<n;i++) {
        temp = i;
        if(A[0][0] == 0) {
            for(j=0;j<=n;j++){
                tempa[i][j] = A[0][j];
            }
            for(j=0;j<=n;j++){
                A[0][j] = A[i+1][j];
            }
            for(j=0;j<=n;j++){
                A[i+1][j] = tempa[i][j];
            }
        }
        i = temp;
    }
    /* pengecekan tukar baris */

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

void main()
{
    int j, i, p, k, besar;
    float x[maks],temp, c, pivot;

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

    masukkan();

    for(i=0;i<n;i++) {
        pivot = A[i][i];
        besar = i;
        if(fabs(pivot) < ep) {
            for(p=i+1;p<n;p++) {
                if(fabs(pivot) < fabs(A[p][i])) {
                    pivot = A[p][i];
                    besar = p;
                }
            }
            tukar_baris(i,besar);
        }
    }
    printf(" Matriks A setelah pertukaran baris : \n");
    puts("----------------------------------------");
    tampil();

    for(i=0;i < n-1;i++) {
        printf(" Matriks A setelah OBE pada kolom ke-%d : \n",i+1);
        puts("----------------------------------------");
        for(j=i+1;j < n;j++) {
            c = A[j][i] / A[i][i];
                for(k=0;k < n+1;k++) {
                    temp = c * A[i][k];
                    A[j][k] = A[j][k] - temp;
                }
        }
        tampil();
    }

    printf(" Ubah elemen jadi 1 \n");
    puts("----------------------------------------");
    for(j=0;j<n;j++) {
        pivot = A[j][j];
        for(k=0;k <= n;k++) {
            A[j][k] = A[j][k] / pivot;
        }
    }
    tampil();


    for(i=0;i < n;i++) {
        for(j=i-1;j >= 0 ;j--) {
            c = A[j][i];
            for(k=0;k <= n+1;k++) {
                temp = c * A[i][k];
                A[j][k] = A[j][k] - temp;
            }
        }

    }

    tampil();

    for(i=0;i < n;i++) {
        x[i]=A[i][n];
        printf("   x[%d] = %g\n",i+1,x[i]);
    }
}
/**** lpuarmy.blogspot.com *****/