test_utils_test.go

package stats_test

// Approximate float comparisons
// Taken from the standard library's math/all_test.go
func tolerance(a, b, e float64) bool {
	// Multiplying by e here can underflow denormal values to zero.
	// Check a==b so that at least if a and b are small and identical
	// we say they match.
	if a == b {
		return true
	}
	d := a - b
	if d < 0 {
		d = -d
	}

	// note: b is correct (expected) value, a is actual value.
	// make error tolerance a fraction of b, not a.
	if b != 0 {
		e = e * b
		if e < 0 {
			e = -e
		}
	}
	return d < e
}
func close(a, b float64) bool     { return tolerance(a, b, 1e-14) }
func veryclose(a, b float64) bool { return tolerance(a, b, 4e-16) }