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RealRoots :: realRootIsolation(RingElement,RR)

realRootIsolation(RingElement,RR)

Synopsis

Description

This method uses a Sturm sequence and a bisection method to isolate real solutions of a polynomialf to a real univariate polynomial and it lists an interval for which each real solution is located

i1 : R = QQ[t]

o1 = R

o1 : PolynomialRing
i2 : f = 45 - 39*t - 34*t^2+38*t^3-11*t^4+t^5

      5      4      3      2
o2 = t  - 11t  + 38t  - 34t  - 39t + 45

o2 : R
i3 : realRootIsolation(f,0.5)

         69    23    23  69    23  207    299  161
o3 = {{- --, - --}, {--, --}, {--, ---}, {---, ---}}
         64    32    32  64     8   64     64   32

o3 : List

See also