Read coefficients of linear equations from file and use jacobi method

Hi,

I did a function that get inputs of equations from user but I am trying to get from a file

Code:

---

void getInput( int numUnKnowns, double** mat ){
    int i, j;


    printf
    (
        "\nEnter values for the specified row and column below ...\n"
        "(The last column is the value for the RHS of the equation.)\n"
    );


    for( i = 0 ; i < numUnKnowns ; i++ )
    {
        mat[i] = (double*) malloc( (numUnKnowns+1)*sizeof(double) );
        puts("");
        for( j = 0 ; j < numUnKnowns+1 ; j++ )
        {
            printf("matrix[%d][%d] : ", i, j);
            if( scanf("%lf", &mat[i][j]) != 1 )
            {
                --j;
                puts("Bad entry ... try again with a 'real' number.");
            }
            while( getchar() != '\n' ) ; /* flush stdin ... */
        }
    }


    printf("\nThe matrix entered:\n\n");
    for( i = 0 ; i < numUnKnowns ; i++ )
    {
        for( j = 0 ; j < numUnKnowns+1 ; j++ ) printf("%+9f ", mat[i][j]);
        puts("");
    }


    printf("\nPress 'Enter' to start iteration ... ");
    getchar();
}

---

can anyone help me how the function read the linear equation from file. assume the file has:
6x + 2y -z = 5
-2x + 4y + z = 8
3x + y + 7z = 3

jacobi function

Code:

---

void jacobiCalcDisplay( int numUnKnowns, double** mat ){
    int* flag;
    int i, j, counter = 0;
    double* res;
    double* var = (double*) malloc( numUnKnowns*sizeof(double) );
    res = (double*) malloc( numUnKnowns*sizeof(double) );
    flag = (int*) malloc( numUnKnowns*sizeof(int) );


    for(i = 0 ; i < numUnKnowns ; i++ )
    var[i] = res[i] = flag[i] = 0;
    printf("The initial value of each array element was set to zero ...\n\n");


    printf( "*********************\n");
    printf( "START CALCULATING ...\n");
    printf( "*********************\n");


    do
    {
        counter++;
        /* for each iteration keep a copy of the old results ... */
        for(i = 0 ; i < numUnKnowns ; i++ )
        {
            var[i] = res[i];
        }


        if( SHOW_ITERS ) printf("\nIteration number %d ...\n", counter);


        for(i = 0 ; i < numUnKnowns ; i++ ) /* calculation */
        {
            res[i] = mat[i][numUnKnowns];
            for(j = 0 ; j < numUnKnowns ; j++ )
                res[i] = res[i] - mat[i][j]*var[j] ;


            res[i] = res[i] + mat[i][i]*var[i] ;
            res[i] = res[i] / mat[i][i] ;
            if( SHOW_ITERS ) printf("%c = %f\n", 'a'+i, res[i]);
            if( fabs(res[i] - var[i]) < EPSILON ) /* stop condition */
            flag[i]++;


            if( counter==MAX_PRINT_ITERS) SHOW_ITERS = 0;
        }


    }while( !checkFlags( numUnKnowns, flag ) );


    printf( "\n********************************\n");
    printf( "The RESULTS of %d ITERATIONS ... \n", counter);
    printf( "********************************\n");


    /*  cross check ...*/


    for( i = 0 ; i < numUnKnowns ; i++)
        var[i] = dotProd( numUnKnowns, mat[i], res );


    showXcheck( numUnKnowns, mat, res, var );


    /* show sol'n vector (again) ... and free up all dynamic memory  */


    printf("\nSolution vector ...\n");
    for( i = 0 ; i < numUnKnowns ; i++)
    {
        printf("%c = %+f\n", 'a'+i, res[i]);
        free(mat[i]);
    }
    free( mat );
    free( flag );
    free( res );
    free( var );
}

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Quote:

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I did a function that get inputs of equations from user but I am trying to get from a file

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No, you found some code that approximates what you need, and now, because you're nothing but a scoop and poop programmer, you're looking for us to give you the code to give you exactly what you need. Pretty sad.

sorry, I did my assignment by myself
I can post all my work.
Am asking how can read from file not asking do that.

> http://cboard.cprogramming.com/cplus...ml#post1083567 is bad enough, and a dupe thread...

Also, you copied it all out of New thread especially for students of C and C++, don't be a ........ing liar.

Quote:

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Originally Posted by memcpy

Also, you copied it all out of New thread especially for students of C and C++, don't be a ........ing liar.

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Please do try to contain yourself.