func bisect()

in internal/stats/alg.go [43:71]

• 29 lines of code
• 12 McCabe index (conditional complexity)

func bisect(f func(float64) float64, low, high, tolerance float64) (float64, bool) {
	flow, fhigh := f(low), f(high)
	if -tolerance <= flow && flow <= tolerance {
		return low, true
	}
	if -tolerance <= fhigh && fhigh <= tolerance {
		return high, true
	}
	if mathSign(flow) == mathSign(fhigh) {
		panic(fmt.Sprintf("root of f is not bracketed by [low, high]; f(%g)=%g f(%g)=%g", low, flow, high, fhigh))
	}
	for {
		mid := (high + low) / 2
		fmid := f(mid)
		if -tolerance <= fmid && fmid <= tolerance {
			return mid, true
		}
		if mid == high || mid == low {
			return mid, false
		}
		if mathSign(fmid) == mathSign(flow) {
			low = mid
			flow = fmid
		} else {
			high = mid
			fhigh = fmid
		}
	}
}