diff options
| -rw-r--r-- | unsupported/Eigen/Polynomials | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/unsupported/Eigen/Polynomials b/unsupported/Eigen/Polynomials index 9e1f6b759..d69abb1be 100644 --- a/unsupported/Eigen/Polynomials +++ b/unsupported/Eigen/Polynomials @@ -64,7 +64,8 @@ namespace Eigen { \endcode evaluates a polynomial at a given point using stabilized Hörner method. - The following code computes the coefficients in the monomial basis of the monic polynomial given through its roots then evaluate it at those roots. + The following code: first computes the coefficients in the monomial basis of the monic polynomial that has the provided roots; + then, it evaluates the computed polynomial, using a stabilized Hörner method. \include PolynomialUtils1.cpp Output: \verbinclude PolynomialUtils1.out @@ -116,11 +117,15 @@ namespace Eigen { (double) floating types and small polynomial degree (<20). \include PolynomialSolver1.cpp - In the example a polynomial with almost conjugate roots is provided to the solver. + + In the above example: + + -# a simple use of the polynomial solver is shown; + -# the accuracy problem with the QR algorithm is presented: a polynomial with almost conjugate roots is provided to the solver. Those roots have almost same module therefore the QR algorithm failed to converge: the accuracy - of the last root is bad. + of the last root is bad; + -# a simple way to circumvent the problem is shown: use doubles instead of floats. - This problem is less visible with double. Output: \verbinclude PolynomialSolver1.out */ |