Linear Algebra and the C Language/a05f

Install and compile this file in your working directory.

/* ------------------------------------ */
/*  Save as :   c00a.c                  */
/* ------------------------------------ */
#include "v_a.h"
/* ------------------------------------ */
#define    RA            R3
#define    CA            C3
/* ------------------------------------ */
int main(void)
{
double a[RA*CA] ={ 4,2,3,
                   5,3,1,
                   8,2,2};
                   
double **A   = ca_A_mR(a,i_mR(RA,CA));

int r = R1;
int c = C2;

  clrscrn();
  printf(" A :");
  p_mR(A,S5,P0,C6);

  printf("    minor(R%d,C%d) = %+.3f\n"
         " cofactor(R%d,C%d) = %+.3f\n\n\n",
               r,c,    minor_R(A, r,c),
               r,c, cofactor_R(A, r,c));
               
  printf(" cofactor(R%d,C%d) = minor(R%d,C%d)*(-1**(R%d+C%d))\n"
         "                   = minor(R%d,C%d)*(%0.0f)\n\n\n",
               r,c, r,c, r,c, r,c, pow(-1,(r+c)));
  stop();

  f_mR(A);

  return 0;
}
/* ------------------------------------ */
/* ------------------------------------ */

Screen output example:

 A :
   +4    +2    +3 
   +5    +3    +1 
   +8    +2    +2 

    minor(R1,C2) = +2.000
 cofactor(R1,C2) = -2.000


 cofactor(R1,C2) = minor(R1,C2)*(-1**(R1+C2))
                 = minor(R1,C2)*(-1)


 Press return to continue.