Mathc matrices/c26a6

Application

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	c06.c

/* ------------------------------------ */
/*  Save as :   c06.c                   */
/* ------------------------------------ */
#include  "v_a.h"
#include    "d.h"
/* --------------------------------- */
int main(void)
{
double   xy[10] ={
  1,   -2,
  2,   -2,
  3,    3,
  4,   -9,
  5,    4,      };

double **XY =  ca_A_mR(xy,i_mR(R5,C2));
double **A  =             i_mR(R5,C5);
double **b =              i_mR(R5,C1);
double **Ab =   i_Abr_Ac_bc_mR(R5,C5,C1);

  clrscrn();
  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_mR(XY,S5,P0,C6);
  printf(" Using the given points, we obtain this matrix\n\n");
  printf("   x**4    x**3    x**2    x**1    x**0    y");
  i_A_b_with_XY_mR(XY,A,b);
  c_A_b_Ab_mR(A,b,Ab);
  p_mR(Ab,S7,P2,C6);
  stop();

  clrscrn();
  printf(" The Gauss Jordan process will reduce this matrix to : \n");
  gj_TP_mR(Ab);
  p_mR(Ab,S7,P2,C6);
  printf("\n The coefficients a, b, c of the curve are :  \n\n");
  p_eq_poly_mR(Ab);
  stop();

  clrscrn();
  printf("    x     y \n");
  p_mR(XY,S5,P0,C6);
  printf("\n");

  printf(" Verify the result : \n\n");
  verify_X_mR(Ab,XY[R1][C1]);
  verify_X_mR(Ab,XY[R2][C1]);
  verify_X_mR(Ab,XY[R3][C1]);
  verify_X_mR(Ab,XY[R4][C1]);
  verify_X_mR(Ab,XY[R5][C1]);
  printf("\n\n\n");
  stop();

  f_mR(XY);
  f_mR(A);
  f_mR(b);
  f_mR(Ab);

  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 points, 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. 
 

 The Gauss Jordan process will reduce this matrix to : 

  +1.00   +0.00   +0.00   +0.00   +0.00   +2.67 
  +0.00   +1.00   +0.00   +0.00   +0.00  -30.33 
  +0.00   +0.00   +1.00   +0.00   +0.00 +117.83 
  -0.00   -0.00   -0.00   +1.00   -0.00 -181.17 
  +0.00   +0.00   +0.00   +0.00   +1.00  +89.00 


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

  y =  +2.667x**4 -30.333x**3 +117.833x**2 -181.167x +89.000
 Press return to continue. 

 
    x     y 

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


 Verify the result : 

 With x =  +1.000,       y = -2.000 
 With x =  +2.000,       y = -2.000 
 With x =  +3.000,       y = +3.000 
 With x =  +4.000,       y = -9.000 
 With x =  +5.000,       y = +4.000 
 Press return to continue.