Linear Algebra and the C Language/a04h

/* ------------------------------------ */
/*  Save as:   c00b.c                   */
/* ------------------------------------ */
#include "v_a.h"
/* ------------------------------------ */
/* ------------------------------------ */
#define RA   R4
#define CA   C3 
#define Cb   C1 
/* ------------------------------------ */
#define FACTOR_E        +1.E-0         
/* ------------------------------------ */
int main(void)
{
double ta[RA*(CA+Cb)]={
/*  x1   x3   x4      */   
    +1,  +0,  +0,/* A */ 
    +0,  +1,  +0,/* B */  
    +0,  -1,  +1,/* C */ 
    -1,  +0,  -1 /* D */ 
};

double tb[RA*(CA+Cb)]={
        +20+10, // A
   +60 -10 -30, // B   
           +20, // C
       -100+30, // D  
};

double **A       =    ca_A_mR(ta,     i_mR(RA,CA));    
double **b       =    ca_A_mR(tb,     i_mR(RA,C1));
double **Pinv    = Pinv_Rn_mR(A,      i_mR(CA,RA),FACTOR_E);           
double **x       =     mul_mR(Pinv,b, i_mR(CA,C1));                

  clrscrn();
  printf(" A:");
  p_mR(A, S5,P1,C6);
  printf(" b:");
  p_mR(b, S5,P1,C6);
   
  printf(" Pinv = V invS_T U_T ");
  pE_mR(Pinv, S12,P4,C6);   
  
  printf(" x = Pinv b ");   
  p_mR(x, S10,P4,C6);  
  stop();  
  
  f_mR(b);   
  f_mR(A);
  f_mR(Pinv);
  f_mR(x); 

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

 A :
 +1.0  +0.0  +0.0 
 +0.0  +1.0  +0.0 
 +0.0  -1.0  +1.0 
 -1.0  +0.0  -1.0 

 b :
+30.0 
+20.0 
+20.0 
-70.0 

 Pinv = V * invS_T * U_T 
 +7.5000e-01  -2.5000e-01  -2.5000e-01  -2.5000e-01 
 -2.5000e-01  +7.5000e-01  -2.5000e-01  -2.5000e-01 
 -5.0000e-01  +5.0000e-01  +5.0000e-01  -5.0000e-01 

 x = Pinv * b 
  +30.0000 
  +20.0000 
  +40.0000 

 Press return to continue.