# include<iostream.h>
# include<math.h>
# include<iomanip.h>
void main()
{
//program d2r7
//driver for routine polcoe
int nfunc,i,j,np = 5;
double x,f,sum,xa[6], ya[6], coeff[6],pi = 3.141593;
for (nfunc = 1; nfunc<=2; nfunc++)
{
if (nfunc == 1)
{
cout<<endl;
cout<< "Sine function from 0 to pi"<<endl;
for (i = 1; i<=np; i++)
{
xa[i] = i * pi /double( np);
ya[i] = sin(xa[i]);
}
}
else
{
if (nfunc ==2)
{
cout<<endl;
cout<< "Exponential function from 0 to 1"<<endl;
for (i = 1; i<=np; i++)
{
xa[i] = 1.0 * i / double(np);
ya[i] = exp(xa[i]);
}
}
else
return;
}
polcoe(xa, ya, np, coeff);
cout<<"coefficients"<<endl;
for (i = 1; i<=np; i++)
cout<<setw(12)<<coeff[i];
cout<<endl;
cout<< " x f[x] polynomial"<<endl;
cout<<setprecision(6)<<setiosflags(ios::fixed);
for (i = 1; i<=10; i++)
{
if (nfunc == 1 )
{
x = (-0.05 + i / 10.0) * pi;
f = sin(x);
}
else
{
if (nfunc == 2)
{
x = (-0.05 + double(i) / 10.0);
f = exp(x);
}
}
sum = coeff[np];
for (j = np - 1; j>=1; j--)
{
sum = coeff[j] + sum * x;
}
cout<<setw(14)<<x;
cout<<setw(14)<<f;
cout<<setw(14)<<sum<<endl;
}
cout<< "**********************************"<<endl;
}
}