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Mathc initiation/Fichiers h : x 18c01c

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Installer et compiler ces fichiers dans votre répertoire de travail.

c01c.c
/* ---------------------------------- */
/* save as c01c.c                     */
/* ---------------------------------- */
#include "x_a.h"
/* ---------------------------------- */
# define   DEGREE     6
# define   COEFF_NB   DEGREE + 1
/* ---------------------------------- */
int main(void)
{
double x =     1;
double remainder;

double *Pa  = I_Px( COEFF_NB);
double *Pt  = I_Px( COEFF_NB);
double *Pqr = I_Px( COEFF_NB);
double *Pq  = I_Px((COEFF_NB-1));

double a[COEFF_NB]={5,3,-2,6,5,-2,-9};

 clrscrn();
 
 c_a_Px(a,Pa);
 printf("\n If P(x) is : \n\n");
 p_Px(Pa);

 printf(" If we divide P(x) by : x - (%+.3f) \n\n",x);
 remainder = compute_horner(x,Pa,Pt,Pqr,Pq);
 p_horner(Pa,Pt,Pqr);

 printf(" The synthetic division indicates that the quotien is :\n\n");
 p_Px(Pq);

 printf(" The synthetic division indicates that P(%+.3f) = %+.3f\n\n",
        x, remainder);
        
 stop();
 
 free(Pa);
 free(Pt);
 free(Pqr);
 free(Pq);

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


Vérifier les calculs à la main. (Voir le premier exemple pour apprendre la méthode de Horner)


Exemple de sortie écran :

 If p_A is : 

   +5.00*x**6  +3.00*x**5  -2.00*x**4  +6.00*x**3  +5.00*x**2  -2.00*x  -9.00  


 If we divide p_A by : x - (+1.000) 


     +5.00     +3.00     -2.00     +6.00     +5.00     -2.00     -9.00   
     +0.00     +5.00     +8.00     +6.00    +12.00    +17.00    +15.00   
   ----------------------------------------------------------------------
     +5.00     +8.00     +6.00    +12.00    +17.00    +15.00     +6.00   


 The synthetic division indicates that the quotien is :

   +5.00*x**5  +8.00*x**4  +6.00*x**3  +12.00*x**2  +17.00*x  +15.00  


 The synthetic division indicates that p_A(+1.000) = +6.000

 Press return to continue.


Fichier de commande gnuplot :
# ---------------------
# Copy and past this file into the screen of gnuplot
#
#
set zeroaxis lt 3 lw 1
plot [-2.:1.5] [-10.:20.]\
      +5.00*x**6  +3.00*x**5  -2.00*x**4  +6.00*x**3  +5.00*x**2  -2.00*x  -9.00
reset
# ---------------------