typename Polynomial<CoefficientType>::RootsType
Polynomial<CoefficientType>::roots() const {
if (!is_univariate)
throw runtime_error(
"getCoefficients is only defined for univariate polynomials");
auto coefficients = getCoefficients();
// need to handle degree 0 and 1 explicitly because Eigen's polynomial solver
// doesn't work for these
int degree = static_cast<int>(coefficients.size()) - 1;
switch (degree) {
case 0:
return Polynomial<CoefficientType>::RootsType(degree);
case 1: {
Polynomial<CoefficientType>::RootsType ret(degree);
ret[0] = -coefficients[0] / coefficients[1];
return ret;
}
default: {
PolynomialSolver<RealScalar, Eigen::Dynamic> solver;
solver.compute(coefficients);
return solver.roots();
break;
}
}
}
typename Polynomial<CoefficientType>::RootsType Polynomial<CoefficientType>::roots() const {
// need to handle degree 0 and 1 explicitly because Eigen's polynomial solver doesn't work for these
int degree = getDegree();
switch (degree) {
case 0:
return Polynomial<CoefficientType>::RootsType(degree);
case 1: {
Polynomial<CoefficientType>::RootsType ret(degree);
ret[0] = -coefficients[0] / coefficients[1];
return ret;
}
default: {
PolynomialSolver<RealScalar, Eigen::Dynamic> solver;
solver.compute(coefficients);
return solver.roots();
break;
}
}
}
