Polynomial

Polynomials of 1 or 2 variables are supported ( Poly and Poly2). Various operations are supported :

• elementary operations between polynomials $(+,-,*,/)$
• setting or getting coefficients
• computing the value of the polynomial for a given value of the variable(s),
• derivating
• computing roots (degre 1 or 2)
• fitting the polynomial to vectors of data.

Here is an example of polynomial fitting :

#include "poly.h"
// ...
Poly pol(2);
pol[0] = 100.; pol[1] = 0.; pol[2] = 0.01; // Setting coefficients
TVector<r_8> x(100);
TVector<r_8> y(100);
TVector<r_8> ey(100);
for(int i=0;i<100;i++) {
  x(i)  = i;
  ey(i) = 10.;
  y(i)  = pol((double) i) + ey(i)*NorRand();
  ey(i) *= ey(i)
}

TVector<r_8> errcoef;
Poly polfit;
polfit.Fit(x,y,ey,2,errcoef);

cout<<"Fit Result"<<polfit<<endl;
cout<<"Errors :"<<errcoef;

Similar operations can be done on polynomials with 2 variables.