// Freeze a counter, using a previously-generated keyset and
// index.
func FreezeWithKeySet(c *counter.Counter, ks *KeySet) *Counter {
values := make([]float64, len(ks.Keys))
for s, idx := range ks.Positions {
values[idx] = c.Get(s)
}
return &Counter{ks, values}
}
// Convert a counter.Counter into a frozen counter, returning the new
// frozen counter and the index required to convert it back.
func Freeze(c *counter.Counter) *Counter {
ks := NewKeySet(c.Keys(), c.Base)
return FreezeWithKeySet(c, ks)
}