Linear Algebra and the C Language/a03o


Install and compile this file in your working directory.

/* ------------------------------------ */
/*  Save as:   c01d.c                   */
/* ------------------------------------ */
#include "v_a.h"
/* ------------------------------------ */
#define   RA R5
#define   CA C3
/* ------------------------------------ */
#define FACTOR_E        +1.E-0         
/* ------------------------------------ */
void fun(void)
{
double **A      =       r_mR(         i_mR(RA,CA),9);
double **Pinv   = Pinv_Rn_mR(A,       i_mR(CA,RA),FACTOR_E);
double **APinv  =     mul_mR(A,Pinv,  i_mR(RA,RA));         
double **APinvA =     mul_mR(APinv,A, i_mR(RA,CA));

  clrscrn();
  printf(" A:");
  p_mR(A, S7,P2,C7);
  
  printf(" Pinv = V invS_T U_T ");
  pE_mR(Pinv, S12,P4,C10); 
  stop();

  clrscrn();  
  printf(" A Pinv:"); 
  p_mR(APinv, S7,P2,C10); 

  printf(" A Pinv A:"); 
  p_mR(APinvA, S7,P2,C10);
  
  printf(" A:");
  p_mR(A, S7,P2,C7);
  
  f_mR(A);
  f_mR(Pinv);
  f_mR(APinv); 
  f_mR(APinvA);  
}
/* ------------------------------------ */
int main(void)
{
time_t t;

  srand(time(&t));
do
{
  fun();


} while(stop_w());

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

Screen output example:

 A :
  -1.00   -1.00   +4.00 
  +6.00   -6.00   -4.00 
  +5.00   +7.00   +7.00 
  +3.00   +8.00   +6.00 
  +9.00   -4.00   -9.00 

 Pinv = V * invS_T * U_T 
 +2.4283e-02  +5.8545e-02  +5.1330e-02  +2.1567e-02  +3.9074e-02 
 -1.0153e-01  -9.9219e-02  -2.9973e-04  +5.6291e-02  +3.6268e-02 
 +1.0552e-01  +7.3025e-02  +5.0103e-02  -7.0949e-03  -6.2428e-02 

 Press return to continue. 


 A*Pinv :
  +0.50   +0.33   +0.15   -0.11   -0.33 
  +0.33   +0.65   +0.11   -0.18   +0.27 
  +0.15   +0.11   +0.61   +0.45   +0.01 
  -0.11   -0.18   +0.45   +0.47   +0.03 
  -0.33   +0.27   +0.01   +0.03   +0.77 

 A*Pinv*A :
  -1.00   -1.00   +4.00 
  +6.00   -6.00   -4.00 
  +5.00   +7.00   +7.00 
  +3.00   +8.00   +6.00 
  +9.00   -4.00   -9.00 

 A :
  -1.00   -1.00   +4.00 
  +6.00   -6.00   -4.00 
  +5.00   +7.00   +7.00 
  +3.00   +8.00   +6.00 
  +9.00   -4.00   -9.00 


 Press   return to continue
 Press X return to stop