/* Computes an approximate root {\tt x} of the function {\tt f} using the
bisection method. We assume that f(neg) is negative and that f(pos) is
positive. Guarantees that a true root will be somewhere in the interval
[x-.5e-5 ... x+.5e-5]. */
float bisection (float neg, float pos) {
...
while (fabs(pos-neg) > 1e-5) {
ave = (pos + neg) / 2;
if (f(ave) < 0) {
neg = ave;
}
else {
pos = ave;
}
}
...
}