Linear Algebra and the C Language/a0g5

/* ------------------------------------ */
/*  Save as :   c00a.c                  */
/* ------------------------------------ */
#include      "v_a.h"
/* ------------------------------------ */
int main(void)
{
double  a[R3*C3]={ 1,2,3,
                   1,2,3,
                   1,2,3 };	
                   
double id[R3*C3]={ 0,1,0,
                   1,0,0,
                   0,0,1 };                
              
double **A  = ca_A_mR(a,    i_mR(R3,C3));
double **ID = ca_A_mR(id,   i_mR(R3,C3));

double **AID = mul_mR(A,ID, i_mR(R3,C3));

  clrscrn();
  printf("Swap two columns:\n\n");
  
  printf(" ID:");
  p_mR(ID, S3,P0,C6);
  
  printf(" A:");
  p_mR(A, S3,P0,C6); 
   
  printf(" A ID:");
  p_mR(AID, S3,P0,C6);
  stop();
      
  f_mR(A);
  f_mR(ID);
  f_mR(AID);

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

                                                                                       
Swap two columns:

 ID:
 +0  +1  +0 
 +1  +0  +0 
 +0  +0  +1 

 A:
 +1  +2  +3 
 +1  +2  +3 
 +1  +2  +3 

 A ID:
 +2  +1  +3 
 +2  +1  +3 
 +2  +1  +3 

 Press return to continue.