BrentSolver
mitsuba\src\libcore\brent.cpp
http://mathworld.wolfram.com/BrentsMethod.html
Applied Mathematics > Numerical Methods > Root-Finding >
Brent's Method
Brent's method is a root-finding algorithm which combines root bracketing, bisection, and inverse quadratic interpolation. It is sometimes known as the van Wijngaarden-Deker-Brent method. Brent's method is implemented in the Wolfram Language as the undocumented option Method -> Brent in FindRoot[eqn, x, x0, x1
].
Brent's method uses a Lagrange interpolating polynomial of degree 2. Brent (1973) claims that this method will always converge as long as the values of the function are computable within a given region containing a root. Given three points ,
, and
, Brent's method fits
as a quadratic function of
, then uses the interpolation formula
![]() | (1) |
Subsequent root estimates are obtained by setting , giving
![]() | (2) |
where
![]() | ![]() | ![]() | (3) |
![]() | ![]() | ![]() | (4) |
with
![]() | ![]() | ![]() | (5) |
![]() | ![]() | ![]() | (6) |
![]() | ![]() | ![]() | (7) |
(Press et al. 1992).
SEE ALSO: Bisection, Brent's Factorization Method, Root Bracketing, Root-Finding Algorithm REFERENCES:
Brent, R. P. Ch. 3-4 in Algorithms for Minimization Without Derivatives. Englewood Cliffs, NJ: Prentice-Hall, 1973.
Forsythe, G. E.; Malcolm, M. A.; and Moler, C. B. §7.2 in Computer Methods for Mathematical Computations. Englewood Cliffs, NJ: Prentice-Hall, 1977.
Press, W. H.; Flannery, B. P.; Teukolsky, S. A.; and Vetterling, W. T. "Van Wijngaarden-Dekker-Brent Method." §9.3 in Numerical Recipes in FORTRAN: The Art of Scientific Computing, 2nd ed. Cambridge, England: Cambridge University Press, pp. 352-355, 1992.
Referenced on Wolfram|Alpha: Brent's Method CITE THIS AS:
Weisstein, Eric W. "Brent's Method." From MathWorld--A Wolfram Web Resource. http://mathworld.wolfram.com/BrentsMethod.html