Bisection Root Fnding Function
Bisection root finding function. Likely the same basic algorithm your graphing calculator uses to find roots. Read more: http://en.wikipedia.org/wiki/Bisection_method
function c = Bisection(f, a, b, n_max, epsilon) % Bisection root finding function % Where f is a function, and a and b are endpoints of the inverval we are searching. % n_max is the maximum cycles we will attempt. % epsilon is the tolerance for determining if we have found a root. fa = f(a); fb = f(b); fprintf('interval [%6.1f, %6.1f]', a,b) fprintf('\nf(a) = %8.1f, f(b) = %8.1f\n', fa, fb) if sign(fa)==sign(fb) disp('No root in the interval') c = 0; else error = b-a; for n=0:n_max error = error/2; c = a + error; fc = f(c); fprintf('\n%6d, c = %10.8f fc = %10.8f error = %10.8f ', n, c, fc, error) if error < epsilon fprintf('\nconvergence\n') break; % root was found else if sign(fa) ~= sign(fc) b = c; fb = fc; else a = c; fa = fc; end end end end

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