Thread: Matrices

Hi,

I would like to find a determinant of a 2*2 matrix.
But there seems to be an error while it is running.

Code:

s=det2(&det,&m1,2,3);
printf("Value of determinant was..%d\n",det);

int det2(int *det,matrix *m1,int row,int col){
  int A,B,C,D;
  row=2;
  col=3;
  A=(*m1).arr[row][col];
  B=(*m1).arr[row+1][col];
  C=(*m1).arr[row][col+1];
  D=(*m1).arr[row+1][col+1];
  *det=(A*D)-(B*C);
  return(0);
}

Where's main()?
Post the complete source code.

here is the code.
getMatrix is another function used to obtain matrix from keyboard.

Code:

int det2(int *val,matrix *m,int row,int col);
main(){
  matrix m1, m2;
  int s,det;
s=getMatrix(&m1);
s=det2(&det,&m1,2,3);
 printf("Value of determinant was..%d\n",det);


int det2(int *det,matrix *m1,int row,int col){
  int A,B,C,D;
  row=2;
  col=3;
  A=(*m1).arr[row][col];
  B=(*m1).arr[row+1][col];
  C=(*m1).arr[row][col+1];
  D=(*m1).arr[row+1][col+1];
  *det=(A*D)-(B*C);
  return(0);
}

Firstly thanks.

And yes, I have a larger matrix and I'm extracting the 2 by 2.

Thats why i picked row[2]col[3], which is the first number then the next number of the matrix should be [2+1][3] right?

For example,

1 2
3 4

I meant if 1 is [2][3] when 2 will be [3][3] and 3 will be [2][4].

No, im am merely taking the matrices and applying the formula.

Thanks all. I try doing it again tmrw. For some reason my laptop doesnt allow the compiler to work. I'll hv to do it on the school's PC.