func NewFloat64RingBuf(maxViewItems int) *Float64RingBuf {
	n := maxViewItems
	r := &Float64RingBuf{
		N:        n,
		Beg:      0,
		Readable: 0,
	}
	r.A = make([]float64, n, n)

	return r
}
func NewFloat64RingBuf(maxViewItems int) *Float64RingBuf {
	n := maxViewItems
	r := &Float64RingBuf{
		N:        n,
		Beg:      0,
		Readable: 0,
	}
	r.A = make([]float64, n, n)

	return r
}
// constructor. NewFloat64RingBuf will allocate internally
// a slice of maxViewItems float64.