zero_brent, an Octave code which finds a zero of a scalar function of a scalar variable, by Richard Brent.
The method does not require the use of derivatives, and does not assume that the function is differentiable.
The information on this web page is distributed under the MIT license.
zero_brent is available in a C version and a C++ version and a Fortran77 version and a Fortran90 version and a MATLAB version and an Octave version and a Python version and an R version.
fsolve_test, an Octave code which calls fsolve() which seeks the solution x of one or more nonlinear equations f(x)=0.
test_zero, an Octave code which defines some test functions for which zeroes can be sought.
zero_itp, an Octave code which finds a zero of a scalar function of a scalar variable, starting from a change of sign interval, using the Interpolate/Truncate/Project (ITP) method, which has faster convergence than the bisection method.
zero_muller, an Octave code which seeks a root of a nonlinear equation using the Muller method, with complex arithmetic.
Original Fortran77 version by Richard Brent; This version by John Burkardt.