can someone help me with this?

this is what my code looks like:

Code:

#include <stdio.h>
int main(void)
{
        FILE *infile;
        int row, col, rows, cols;
        double **a, *b, *c, sum=0.0;
/* Define infile */
        infile = fopen("matrix5.dat", "r");
        if(infile==NULL){
                printf("matrix5.dat does not exist.\n");
        exit(100);
        }
/* read rows and cols */
        fscanf(infile, "%d %d", &rows, &cols);
        printf("\nrows = %2d cols = %2d\n", row, cols);
/* Allocate memory to **a */
        a=(double **)calloc((size_t)rows, sizeof(double *));
/* Allocate memory for a[row], row=0, 1, ..., rows-1 */
        for(row = 0; row<rows; row++){
                a[row] = (double *)calloc((size_t)cols, sizeof(double));
                if(a[row] == NULL){
                printf("\n**calloc failed in allocating memory for a[%d]\n", row
);
        exit(101);
        }
        }
/* Allocate memory for b[rows] and c[rows] */
        b = (double *)calloc((size_t)rows, sizeof(double));
        c = (double *)calloc((size_t)rows, sizeof(double));
        if(b==NULL || c==NULL){
        printf("** calloc failed in allocating memory for b[] or c[]\n");
        exit(102);
        }
/* read all rows and save the values in a[][] */
        printf("\na[][]:\n");
        for(row=0; row<rows; row++){
        printf("[%d]", row);
        for(col=0; col<cols; col++)
        fscanf(infile, "%lf", a[row]+col);
        for(col=0; col<cols; col++)
        printf("%9.3f", a[row][col]);
        printf("\n");
        }
/* read b[] from the last line */
        printf("\nb[]");
        for(row=0; row<rows; row++)
        fscanf(infile, "%lf", b+row);
        for(row=0; row<rows; row++)
        printf("%9.3f", b[row]);
        printf("\n");
/* print a[][] */
        printf("[%d]", row);
        for(col=0; col<cols; col++)
        fscanf(infile, "%lf", a[row]+col);
        for(col=0; col<cols; col++)
        printf("%9.3f", a[row]+col);
        printf("\n");
        }
/* read b[] from the last line */
        printf("\nb[]");
        for(row=0; row<rows; row++)
        fscanf(infile, "%lf", b+row);
        for(row=0; row<rows; row++)
        printf("%9.3f", b[row]);
        printf("\n");
/* print a[][] */
        printf("[%d]", row);
        for(col=0; col<cols; col++)
        fscanf(infile, "%lf", a[row]+col);
        for(col=0; col<cols; col++)
        printf("%9.3f", a[row]+col);
        printf("\n");
/* print b[] */
/* compute c[] = a[][] * b[] */
        for(row=0; row<rows; row++){
        for(col=0, sum=0.0; col<cols; col++)
        sum = sum + (a[row][col] *b[col]);
        c[row]=sum;
        }
        printf("\n");
/* print c[] */
        printf("c[]");
        for(row=0; row<rows; row++)
        printf("%9.3f", c[row]);
        printf("\n");
/* return memory */
        free(b);
        free(c);
        for(col = 0; col<cols; col++)
        free(a[col]);
        free(a);
/* close infile */
        fclose(infile);
        exit(0);
}

and when i compile it i get:

rows =  4 cols =  7

a[][]:
[0]   10.000    9.000    8.000    7.000    6.000    5.000    4.000
[1]    9.000   11.000   -6.000    8.000    3.000   -2.000    5.000
[2]    8.000   -6.000   12.000   10.000   -8.000   -6.000    4.000
[3]    7.000    8.000   10.000   14.000   13.000   -6.000    5.000
[4]    6.000    3.000   -8.000   13.000   16.000   14.000   -9.000
[5]    5.000   -2.000   -6.000   -6.000   17.000   15.000   14.000
[6]    4.000    5.000    4.000    5.000   -9.000   19.000   10.000

b[]    1.000    2.000   -1.000    4.000   -3.000    2.000    1.000
[7]    0.000    0.000    0.000    0.000    0.000    0.000    0.000

c[]   44.000   61.000   40.000   23.000   43.000  -24.000  105.000

how do i get rid of the [7] line? i can't find it. i keep looking over and over again.

You've got two lines marked /*print a[][] */, one before the b and one after the b. (Note that you should put code in code tags.)

that doesn't really help...
which line is it?
i also get the wrong number of rows
apparently i should be getting 7

You complained that your a matrix was printing twice, I pointed out where you had copied your code that printed a in two places. I'm not sure what else you need here.

Get some coffee, dude. Zero to 6 is 7 lines.

Jeez dude... indent your code!

not my [a] matrix
i'm not supposed to have a [7] line after my [b] line

I suggest that you try:
1. Indenting the code.
2. Fixing the balance of your brackets, so that the indentation matches the intent of the code - currently there (at least) one too many end-braces.
3. Recompile.

I very sure that the current code doesn't compile, which probably means that if your posted output is from some version of this code, it is certainly not the posted version.

--
Mats

there are the same number of opening and closing braces
unless i'm missing something
and the code does compile:

Code:

#include <stdio.h>
int main(void)
{
        FILE *infile;
        int row, col, rows, cols;
        double **a, *b, *c, sum=0.0;
/* Define infile */
        infile = fopen("matrix5.dat", "r");
        if(infile==NULL)
        {
                printf("matrix5.dat does not exist.\n");
                exit(100);
        }
/* read rows and cols */
        fscanf(infile, "%d %d", &rows, &cols);
        printf("\nrows = %2d cols = %2d\n", row, cols);
/* Allocate memory to **a */
        a=(double **)calloc((size_t)rows, sizeof(double *));
/* Allocate memory for a[row], row=0, 1, ..., rows-1 */
        for(row = 0; row<rows; row++)
        {
                a[row] = (double *)calloc((size_t)cols, sizeof(double));
                if(a[row] == NULL)
                        {
                        printf("\n**calloc failed in allocating memory for a[%d]\n", row);
                        exit(101);
                        }
        }
/* Allocate memory for b[rows] and c[rows] */
        b = (double *)calloc((size_t)rows, sizeof(double));
        c = (double *)calloc((size_t)rows, sizeof(double));
        if(b==NULL || c==NULL)
        {
                printf("** calloc failed in allocating memory for b[] or c[]\n");
                exit(102);
        }
/* read all rows and save the values in a[][] */
        printf("\na[][]:\n");
        for(row=0; row<rows; row++)
        {
                printf("[%d]", row);
                for(col=0; col<cols; col++)
                        fscanf(infile, "%lf", a[row]+col);
                        for(col=0; col<cols; col++)
                                printf("%9.3f", a[row][col]);
                printf("\n");
        }
/* read b[] from the last line */
        printf("\nb[]");
        for(row=0; row<rows; row++)
        fscanf(infile, "%lf", b+row);
        for(row=0; row<rows; row++)
        printf("%9.3f", b[row]);
        printf("\n");
/* print a[][] */
        printf("[%d]", row);
        for(col=0; col<cols; col++)
        fscanf(infile, "%lf", a[row]+col);
        for(col=0; col<cols; col++)
        printf("%9.3f", a[row]+col);
        printf("\n");
/* print b[] */
/* compute c[] = a[][] * b[] */
        for(row=0; row<rows; row++)
        {
                for(col=0, sum=0.0; col<cols; col++)
                        sum = sum + (a[row][col] *b[col]);
                c[row]=sum;
        }
        printf("\n");
/* print c[] */
        printf("c[]");
        for(row=0; row<rows; row++)
                printf("%9.3f", c[row]);
        printf("\n");
/* return memory */
        free(b);
        free(c);
        for(col = 0; col<cols; col++)
        free(a[col]);
        free(a);
/* close infile */
        fclose(infile);
        exit(0);
}

Originally Posted by burninfrost296

there are the same number of opening and closing braces
unless i'm missing something
and the code does compile:

Now it does, but your original example does not. I edited your post to add in bbcode tags, but it looks like you still have some more work to do in order to indent your code consistently, though it is good to see that you made some effort in that direction.

Not in your first post [or there is something else that confuses Emacs' auto-indentation feature], but it seems like that is fixed now.

Your indentation is still a bit wonky, but a lot better than before.

Code:

                for(col=0; col<cols; col++)
                        fscanf(infile, "%lf", a[row]+col);
                        for(col=0; col<cols; col++)
                                printf("%9.3f", a[row][col]);

For example here, for second loop is NOT part of the first loop (and it would be a very bad thing if it was, since it is using the same variable.

--
Mats

i still get the same thing when i compile it
with the [7] line after the b[] line
and i get 4 rows, when i obviously have 7 in my a matrix
did i use the wrong %?

Originally Posted by burninfrost296

not my [a] matrix
i'm not supposed to have a [7] line after my [b] line

Your code:

Code:

/* print a[][] */
        printf("[%d]", row);
        for(col=0; col<cols; col++)
        fscanf(infile, "%lf", a[row]+col);
        for(col=0; col<cols; col++)
        printf("%9.3f", a[row]+col);
        printf("\n");
        }
/* read b[] from the last line */
        printf("\nb[]");
        for(row=0; row<rows; row++)
        fscanf(infile, "%lf", b+row);
        for(row=0; row<rows; row++)
        printf("%9.3f", b[row]);
        printf("\n");
/* print a[][] */
        printf("[%d]", row);
        for(col=0; col<cols; col++)
        fscanf(infile, "%lf", a[row]+col);
        for(col=0; col<cols; col++)
        printf("%9.3f", a[row]+col);
        printf("\n");
/* print b[] */

Print a Print b Print a again ("row 7") (You've changed your comments since the first post, but not the code.)

did you see my new code?
i changed it
but i still get the same problem

Originally Posted by burninfrost296

did you see my new code?
i changed it
but i still get the same problem

No, you changed the comments. You didn't change the code:

Code:

/* read all rows and save the values in a[][] */
        printf("\na[][]:\n");
        for(row=0; row<rows; row++)
        {
                printf("[%d]", row);
                for(col=0; col<cols; col++)
                        fscanf(infile, "%lf", a[row]+col);
                        for(col=0; col<cols; col++)
                                printf("%9.3f", a[row][col]);
                printf("\n");
        }
/* read b[] from the last line */
        printf("\nb[]");
        for(row=0; row<rows; row++)
        fscanf(infile, "%lf", b+row);
        for(row=0; row<rows; row++)
        printf("%9.3f", b[row]);
        printf("\n");
/* print a[][] */
        printf("[%d]", row);
        for(col=0; col<cols; col++)
        fscanf(infile, "%lf", a[row]+col);
        for(col=0; col<cols; col++)
        printf("%9.3f", a[row]+col);
        printf("\n");