Mathc initiation/a598

Sommaire

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	c0fs.c

/* ---------------------------------- */
/* save as c0fs.c                     */
/* ---------------------------------- */
#include "x_hfile.h"
/* ---------------------------------- */
#include      "f0.h"
/* ---------------------------------- */
int main(void)
{
double     T =  PI;
	
double omega = (2.*PI/T);

double     a =  0.;
double     b =  PI;

double     a0 =  1./T * fourier_a0(f, a,b);
double     an =  2./T * fourier_an(f, a,b, omega, 1);

double     b1 =  2./T * fourier_bn(f, a,b, omega, 1);
double     b2 =  2./T * fourier_bn(f, a,b, omega, 2);
double     b3 =  2./T * fourier_bn(f, a,b, omega, 3);
double     b4 =  2./T * fourier_bn(f, a,b, omega, 4);
double     b5 =  2./T * fourier_bn(f, a,b, omega, 5);
double     b6 =  2./T * fourier_bn(f, a,b, omega, 6);
double     b7 =  2./T * fourier_bn(f, a,b, omega, 7);
double     b8 =  2./T * fourier_bn(f, a,b, omega, 8);

 clrscrn();

 printf("              _+oo_                                   \n"
        "             \\                                       \n"
        " S(t) = a0 + | an cos(omega* n*t) + bn sin(omega *n*t)\n"
        "             /_____                                   \n"
        "              n = 1                             \n\n\n\n");

 printf(" a0 =  %.6f       \n",a0);
 printf(" an =  %.6f     \n\n",an);
 
     printf(" S(x) = %.9f\\\n" 
        " %.9f*sin(%.9f* 1*x)\\\n"
        " %.9f*sin(%.9f* 2*x)\\\n"
        " %.9f*sin(%.9f* 3*x)\\\n"
        " %.9f*sin(%.9f* 4*x)\\\n"
        " %.9f*sin(%.9f* 5*x)\\\n"
        " %.9f*sin(%.9f* 6*x)\\\n"
        " %.9f*sin(%.9f* 7*x)\\\n"        
        " %.9f*sin(%.9f* 8*x)\n"
        "     ...        \n\n\n",
                      a0,   
                      b1,      omega,
                      b2,      omega,
                      b3,      omega,
                      b4,      omega,   
                      b5,      omega,
                      b6,      omega,
                      b7,      omega,
                      b8,      omega);  
 stop();

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

Exemple de sortie écran :

              _+oo_                                   
             \                                       
 S(t) = a0 + | an cos(omega* n*t) + bn sin(omega *n*t)
             /_____                                   
              n = 1                             



 a0 =  1.570796       
 an =  0.000000     

 S(x) = 1.570796327\
 -1.000000005*sin(2.000000000* 1*x)\
 -0.500000043*sin(2.000000000* 2*x)\
 -0.333333480*sin(2.000000000* 3*x)\
 -0.250000347*sin(2.000000000* 4*x)\
 -0.200000678*sin(2.000000000* 5*x)\
 -0.166667841*sin(2.000000000* 6*x)\
 -0.142859010*sin(2.000000000* 7*x)\
 -0.125002792*sin(2.000000000* 8*x)
     ...        


 Press return to continue.

Fourier serie f(x) = x with x[0..Pi]

Fichier de commande gnuplot :

# ---------------------
# Copy and past this file into the screen of gnuplot
#
#
plot [0.:pi] [0.:pi]\
x,\
1.570796327\
 -1.000000005*sin(2.000000000* 1*x)\
 -0.500000043*sin(2.000000000* 2*x)\
 -0.333333480*sin(2.000000000* 3*x)\
 -0.250000347*sin(2.000000000* 4*x)\
 -0.200000678*sin(2.000000000* 5*x)\
 -0.166667841*sin(2.000000000* 6*x)\
 -0.142859010*sin(2.000000000* 7*x)\
 -0.125002792*sin(2.000000000* 8*x)

reset