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Mathc complexes/071

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Application

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c00f.c
/* ------------------------------------ */
/*  Save as :   c00f.c                  */
/* ------------------------------------ */
#include "w_a.h" 
/* ------------------------------------ */
#define   RA R5
#define   CA C5
#define   Cb C1 
/* ------------------------------------ */
/* ------------------------------------ */
int main(void)
{
double   xy[10] ={
  1,   -2,
  2,   -2,
  3,    3,
  4,   -9,
  5,    4,      };

   
double ab[RA*(CA+Cb)]={
/* x**4    x**3    x**2    x**1    x**0    y   */
  +1,     +1,     +1,     +1,     +1,     -2,   
 +16,     +8,     +4,     +2,     +1,     -2,   
 +81,    +27,     +9,     +3,     +1,     +3,   
+256,    +64,    +16,     +4,     +1,     -9,   
+625,   +125,    +25,     +5,     +1,     +4,             
}; 


double **XY =  ca_A_mRZ(xy,i_mZ(R5,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**4 + bx**3 + cx**2 + dx + e       \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");
  printf("   x**4    x**3    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);
  stop();

  clrscrn();
  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,P3,C6);
  printf(" The coefficients a, b, c, d of the curve are : \n\n"
         "  y = %+.3fx**4 %+.3fx**3 %+.3fx**2 %+.3fx  %+.3f\n\n"
            ,x[R1][C1],x[R2][C1],x[R3][C1],x[R4][C1],x[R5][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**4 + bx**3 + cx**2 + dx + e       

 that passes through the points.             

    x     y
   +1    -2 
   +2    -2 
   +3    +3 
   +4    -9 
   +5    +4 


 Using the given XY, we obtain this matrix.
   x**4    x**3    x**2    x**1    x**0    y
  +1.00   +1.00   +1.00   +1.00   +1.00   -2.00 
 +16.00   +8.00   +4.00   +2.00   +1.00   -2.00 
 +81.00  +27.00   +9.00   +3.00   +1.00   +3.00 
+256.00  +64.00  +16.00   +4.00   +1.00   -9.00 
+625.00 +125.00  +25.00   +5.00   +1.00   +4.00 

 Press return to continue. 


 Q :
   +0.0015    +0.0485    +0.4216    +0.8487    +0.3156 
   +0.0235    +0.2856    +0.7083    -0.1335    -0.6312 
   +0.1190    +0.6174    +0.2365    -0.3877    +0.6312 
   +0.3762    +0.6420    -0.4915    +0.3242    -0.3156 
   +0.9185    -0.3504    +0.1519    -0.0805    +0.0631 

 R :
 +680.4256  +142.3006   +30.1502    +6.5033    +1.4388 
   +0.0000   +16.2950    +8.2602    +3.2880    +1.2431 
   -0.0000    -0.0000    +1.3158    +1.3410    +1.0268 
   +0.0000    +0.0000    +0.0000    +0.3128    +0.5711 
   -0.0000    -0.0000    -0.0000    -0.0000    +0.0631 

 Press return to continue. 


 Q_T :
 +1.4697e-03  +2.3515e-02  +1.1904e-01  +3.7624e-01  +9.1854e-01 
 +4.8534e-02  +2.8560e-01  +6.1737e-01  +6.4201e-01  -3.5037e-01 
 +4.2165e-01  +7.0827e-01  +2.3651e-01  -4.9150e-01  +1.5186e-01 
 +8.4868e-01  -1.3354e-01  -3.8774e-01  +3.2419e-01  -8.0475e-02 
 +3.1560e-01  -6.3119e-01  +6.3119e-01  -3.1560e-01  +6.3119e-02 

 invR :
 +1.4697e-03  -1.2834e-02  +4.6895e-02  -9.6700e-02  +3.3138e-01 
 +0.0000e+00  +6.1368e-02  -3.8527e-01  +1.0067e+00  -4.0502e+00 
 +0.0000e+00  -0.0000e+00  +7.6002e-01  -3.2586e+00  +1.7121e+01 
 +0.0000e+00  +0.0000e+00  +0.0000e+00  +3.1973e+00  -2.8930e+01 
 +0.0000e+00  -0.0000e+00  +0.0000e+00  +0.0000e+00  +1.5843e+01 

 Press return to continue. 


 Solving this system yields a unique
 least squares solution, namely   

 x = invR * Q_T * b :
    +2.667 
   -30.333 
  +117.833 
  -181.167 
   +89.000 

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

  y = +2.667x**4 -30.333x**3 +117.833x**2 -181.167x  +89.000