48 lines
1.2 KiB
C++
48 lines
1.2 KiB
C++
// (C) Copyright Gennadiy Rozental 2001-2015.
|
|
// Distributed under the Boost Software License, Version 1.0.
|
|
// (See accompanying file LICENSE_1_0.txt or copy at
|
|
// http://www.boost.org/LICENSE_1_0.txt)
|
|
//
|
|
// See http://www.boost.org/libs/test for the library home page.
|
|
//
|
|
|
|
|
|
//[snippet8
|
|
double find_root( double (*f)(double),
|
|
double low_guess,
|
|
double high_guess,
|
|
std::vector<double>& steps,
|
|
double tolerance )
|
|
{
|
|
double solution;
|
|
bool converged = false;
|
|
|
|
while(not converged)
|
|
{
|
|
double temp = (low_guess + high_guess) / 2.0;
|
|
steps.push_back( temp );
|
|
|
|
double f_temp = f(temp);
|
|
double f_low = f(low_guess);
|
|
|
|
if(abs(f_temp) < tolerance)
|
|
{
|
|
solution = temp;
|
|
converged = true;
|
|
}
|
|
else if(f_temp / abs(f_temp) == f_low / abs(f_low))
|
|
{
|
|
low_guess = temp;
|
|
converged = false;
|
|
}
|
|
else
|
|
{
|
|
high_guess = temp;
|
|
converged = false;
|
|
}
|
|
}
|
|
|
|
return solution;
|
|
}
|
|
//]
|