How to use boost bisection?
This is an example use of bisect
. Consider solving the equation x^2 - 3x + 1 = 0
:
struct TerminationCondition {
bool operator() (double min, double max) {
return abs(min - max) <= 0.000001;
}
};
struct FunctionToApproximate {
double operator() (double x) {
return x*x - 3*x + 1; // Replace with your function
}
};
// ...
using boost::math::tools::bisect;
double from = 0; // The solution must lie in the interval [from, to], additionally f(from) <= 0 && f(to) >= 0
double to = 1;
std::pair<double, double> result = bisect(FunctionToApproximate(), from, to, TerminationCondition());
double root = (result.first + result.second) / 2; // = 0.381966...
EDIT: Alternatively, this is how you can use it with custom functions:
double myF(double x) {
return x*x*x;
}
double otherF(double x) {
return log(abs(x));
}
// ...
std::pair<double, double> result1 = bisect(&myF, from, to, TerminationCondition());
std::pair<double, double> result2 = bisect(&otherF, 0.1, 1.1, TerminationCondition());