Linear Algebra and the C Language/a0i1

Install and compile this file in your working directory.

/* ------------------------------------ */
/*  Save as :   c00b.c                  */
/* ------------------------------------ */
#include "v_a.h"
/* ------------------------------------ */
void fun(int r)
{
double **A   = rskewsymmetric_mR(  i_mR(r,r), 9);

  clrscrn();
    
  printf(" If Rn is odd  det_R(A)  = 0\n\n"
         " A[R%d,C%d] : \n",rsize_R(A),csize_R(A));
  p_mR(A, S7,P3,C6);
 
  printf(" det_R(A)  = %+.4f\n",det_R(A));
     
  f_mR(A);
}
/* ------------------------------------ */
int main(void)
{
time_t t;

  srand(time(&t));

do
{
  fun(rp_I(R3)+R2);

} while(stop_w());

  return 0;
}

/* ------------------------------------ */
/* ------------------------------------ */

If the number of rows is odd the determinant is zero

Screen output example:

                                                                                       
 If Rn is odd  det_R(A)  = 0

 A[R4,C4] : 

 +0.000  +1.000  +4.000  +3.000 
 -1.000  +0.000  -8.000  +8.000 
 -4.000  +8.000  +0.000  -6.000 
 -3.000  -8.000  +6.000  +0.000 

 det_R(A)  = +3844.0000

 Press   return to continue
 Press X return to stop    

 If Rn is odd  det_R(A)  = 0

 A[R5,C5] : 

 +0.000  +2.000  +3.000  +8.000  -1.000 
 -2.000  +0.000  +9.000  -3.000  +2.000 
 -3.000  -9.000  +0.000  -2.000  +2.000 
 -8.000  +3.000  +2.000  +0.000  +7.000 
 +1.000  -2.000  -2.000  -7.000  +0.000 

 det_R(A)  = +0.0000

 Press   return to continue
 Press X return to stop