func (b *Float64RingBuf) Adopt(me []float64) {
	n := len(me)
	if n > b.N {
		b.A = me
		b.N = n
		b.Beg = 0
		b.Readable = n
	} else {
		// we already have a larger buffer, reuse it.
		copy(b.A, me)
		b.Beg = 0
		b.Readable = n
	}
}
func (b *Float64RingBuf) Adopt(me []float64) {
	n := len(me)
	if n > b.N {
		b.A = me
		b.N = n
		b.Beg = 0
		b.Readable = n
	} else {
		// we already have a larger buffer, reuse it.
		copy(b.A, me)
		b.Beg = 0
		b.Readable = n
	}
}
// Adopt(): non-standard.
//
// For efficiency's sake, (possibly) take ownership of
// already allocated slice offered in me.
//
// If me is large we will adopt it, and we will potentially then
// write to the me buffer.
// If we already have a bigger buffer, copy me into the existing
// buffer instead.