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#include <2geom/sbasis-poly.h>
namespace Geom{
/** Changes the basis of p to be sbasis.
\param p the Monomial basis polynomial
\returns the Symmetric basis polynomial
This algorithm is horribly slow and numerically terrible. Only for testing.
*/
SBasis poly_to_sbasis(Poly const & p) {
SBasis x = Linear(0, 1);
SBasis r;
for(int i = p.size()-1; i >= 0; i--) {
r = SBasis(Linear(p[i], p[i])) + multiply(x, r);
}
r.normalize();
return r;
}
/** Changes the basis of p to be monomial.
\param p the Symmetric basis polynomial
\returns the Monomial basis polynomial
This algorithm is horribly slow and numerically terrible. Only for testing.
*/
Poly sbasis_to_poly(SBasis const & sb) {
if(sb.isZero())
return Poly();
Poly S; // (1-x)x = -1*x^2 + 1*x + 0
Poly A, B;
B.push_back(0);
B.push_back(1);
A.push_back(1);
A.push_back(-1);
S = A*B;
Poly r;
for(int i = sb.size()-1; i >= 0; i--) {
r = S*r + sb[i][0]*A + sb[i][1]*B;
}
r.normalize();
return r;
}
};
/*
Local Variables:
mode:c++
c-file-style:"stroustrup"
c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
indent-tabs-mode:nil
fill-column:99
End:
*/
// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :
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