package forecast

func DifferenceAtLeast(previous float64, current float64, threshold float64) bool {
	return abs(current-previous) >= threshold
}

func CrossesAtOrAbove(previous float64, current float64, threshold float64) bool {
	return previous < threshold && current >= threshold
}

func CrossesBelow(previous float64, current float64, threshold float64) bool {
	return previous >= threshold && current < threshold
}

func abs(value float64) float64 {
	if value < 0 {
		return -value
	}
	return value
}