tsuz/go-pine

package pine

// Crossunder generates ValueSeries of ketler channel's middle, upper and lower in that order.
func Crossunder(a, b ValueSeries) ValueSeries {
    c := OperateWithNil(a, b, "crossunder", func(av, bv *Value) *Value {
        if av == nil || bv == nil {
            return nil
        }
        zero := &Value{
            t: av.t,
            v: 0,
        }
        if av.prev == nil || bv.prev == nil {
            return zero
        }
        if av.v < bv.v && av.prev.v > bv.prev.v {
            return &Value{
                t: av.t,
                v: 1.0,
            }
        }
        return zero
    })

    return c
}