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Mathc complexes/06x

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Application

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c00b.c
/* ------------------------------------ */
/*  Save as :   c00b.c                  */
/* ------------------------------------ */
#include "w_a.h" 
/* ------------------------------------ */
#define   RA R3
#define   CA C3
#define   Cb C1 
/* ------------------------------------ */
/* ------------------------------------ */
int main(void)
{
double   xy[6] ={1, -9,
                 2,  8,
                 3, -8,   };

   
double ab[RA*(CA+Cb)]={
/* x**2    x**1    x**0    y   */
  +1,     +1,     +1,     -9,   
  +4,     +2,     +1,     +8,   
  +9,     +3,     +1,     -8,        
}; 

double **XY =  ca_A_mRZ(xy,i_mZ(R3,C2));

double **Ab =  ca_A_mRZ(ab,i_Abr_Ac_bc_mZ(RA,CA,Cb));
double **A  = c_Ab_A_mZ(Ab,i_mZ(RA,CA));
double **b  = c_Ab_b_mZ(Ab,i_mZ(RA,Cb));

double **Q    = i_mZ(RA,CA);
double **R    = i_mZ(CA,CA);

double **invR = i_mZ(CA,CA);
double **Q_T  = i_mZ(CA,RA);


double **invR_Q_T = i_mZ(CA,RA);
double **x        = i_mZ(CA,Cb); // x = invR * Q_T * b

  clrscrn();
  printf("\n");
  printf(" Find the coefficients a, b, c  of the curve   \n\n");
  printf("      y =  ax**2 + bx + c           (x**0 = 1) \n\n");
  printf(" that passes through the points.               \n\n");
  printf("    x     y");
  p_mRZ(XY,S5,P0,C6);
  printf("\n");
  printf(" Using the given XY, we obtain this matrix.\n\n");
  printf("   x**2   x**1     x**0 =  y");
  p_mRZ(Ab,S7,P2,C6);
  stop();

  clrscrn();
  QR_mZ(A,Q,R);    
  printf(" Q :");
  p_mRZ(Q,S10,P4,C6); 
  printf(" R :");
  p_mRZ(R,S10,P4,C6);

  transpose_mZ(Q,Q_T);   
  printf(" Q_T :");
  pE_mRZ(Q_T,S12,P4,C6); 
  inv_mZ(R,invR); 
  printf(" invR :");
  pE_mRZ(invR,S12,P4,C6);
  stop();
  
  clrscrn();
  printf(" Solving this system yields a unique\n"
         " least squares solution, namely   \n\n");
  mul_mZ(invR,Q_T,invR_Q_T);
  mul_mZ(invR_Q_T,b,x);
  printf(" x = invR * Q_T * b :");
  p_mRZ(x,S10,P2,C6);
  printf(" The coefficients a, b, c, of the curve are : \n\n"
         "  y = %+.2fx**2  %+.2fx  %+.2f \n\n"
            ,x[R1][C1],x[R2][C1],x[R3][C1]);  
  stop();

  f_mZ(XY);  
  f_mZ(A);
  f_mZ(b);
  f_mZ(Ab);
  f_mZ(Q);
  f_mZ(Q_T);
  f_mZ(R);
  f_mZ(invR);  
  f_mZ(invR_Q_T); 
  f_mZ(x); 

  return 0;
}
/* ------------------------------------ */
/* ------------------------------------ */
Exemple de sortie écran :
 Find the coefficients a, b, c  of the curve   

      y =  ax**2 + bx + c           (x**0 = 1) 

 that passes through the points.               

    x     y
   +1    -9 
   +2    +8 
   +3    -8 


 Using the given XY, we obtain this matrix.

   x**2   x**1     x**0 =  y
  +1.00   +1.00   +1.00   -9.00 
  +4.00   +2.00   +1.00   +8.00 
  +9.00   +3.00   +1.00   -8.00 

 Press return to continue. 


 Q :
   +0.1010    +0.7184    +0.6882 
   +0.4041    +0.6025    -0.6882 
   +0.9091    -0.3476    +0.2294 

 R :
   +9.8995    +3.6365    +1.4142 
   -0.0000    +0.8806    +0.9733 
   +0.0000    +0.0000    +0.2294 

 Q_T :
 +1.0102e-01  +4.0406e-01  +9.0914e-01 
 +7.1841e-01  +6.0254e-01  -3.4762e-01 
 +6.8825e-01  -6.8825e-01  +2.2942e-01 

 invR :
 +1.0102e-01  -4.1714e-01  +1.1471e+00 
 +0.0000e+00  +1.1355e+00  -4.8177e+00 
 +0.0000e+00  -0.0000e+00  +4.3589e+00 

 Press return to continue. 


 Solving this system yields a unique
 least squares solution, namely   

 x = invR * Q_T * b :
    -16.50 
    +66.50 
    -59.00 

 The coefficients a, b, c, of the curve are : 

  y = -16.50x**2  +66.50x  -59.00 

 Press return to continue.