Golang ScanRight Examples

Example #1

File: golomb.go Project: samuell/exp

func WriteUint(w *bit.Writer, v uint) {
	if v == 0 {
		w.WriteBit(1)
		return
	}

	nbits := bit.ScanRight(uint64(v)) + 1

	w.WriteBits(0, nbits)
	rbits := bit.Reverse(uint64(v), nbits)
	w.WriteBits(rbits, nbits)
}

Example #2

File: golomb.go Project: samuell/exp

func WriteInt(w *bit.Writer, v int) {
	if v == 0 {
		w.WriteBit(1)
		return
	}

	sign := 0
	if v < 0 {
		sign = 1
		v = -v
	}

	nbits := bit.ScanRight(uint64(v)) + 1

	w.WriteBits(0, nbits)
	rbits := bit.Reverse(uint64(v), nbits)
	w.WriteBits(rbits, nbits)
	w.WriteBit(sign)
}

Example #3

File: encoding.go Project: samuell/exp

func (s *State) Encode() []byte {
	enc := arith.NewEncoder()

	historic := s.Historic().Cubes
	baseline := s.Baseline().Cubes
	current := s.Current().Cubes

	mzeros := mZeros()
	items := []int{}
	for i := range current {
		cube, base := &current[i], &baseline[i]
		if *cube == *base {
			mzeros.Encode(enc, 0)
		} else {
			mzeros.Encode(enc, 1)
			items = append(items, i)
		}
	}

	for _, i := range items {
		cube := &current[i]
		mzeros.Encode(enc, uint(cube.Interacting^1))
	}

	for _, i := range items {
		cube, base := &current[i], &baseline[i]
		v := uint(cube.Largest ^ base.Largest)
		mzeros.Encode(enc, v&1)
		mzeros.Encode(enc, v>>1)
	}

	items6 := Index6(items, len(baseline))
	SortByZ(items6, Delta6(historic, baseline))
	get6 := Extra6(historic, baseline, current)

	max := uint64(0)
	for _, i := range items6 {
		ext := uint64(bit.ZEncode(int64(get6(i))))
		if max < ext {
			max = ext
		}
	}

	if max == 0 {
		mzeros.Encode(enc, 1)
		enc.Close()
		return enc.Bytes()
	}

	nbits := bit.ScanRight(max) + 1
	for i := 0; i < int(nbits); i += 1 {
		mzeros.Encode(enc, 0)
	}
	mzeros.Encode(enc, 1)

	mvalues := mValues(nbits)
	for _, i := range items6 {
		val := uint(bit.ZEncode(int64(get6(i))))
		mvalues.Encode(enc, val)
	}

	enc.Close()
	return enc.Bytes()
}

Example #4

File: models.go Project: samuell/exp

func (tree Tree) NBits() uint { return bit.ScanRight(uint64(tree.syms())) }

Example #5

File: optimizer.go Project: samuell/exp

func main() {
	flag.Parse()

	rand.Seed(time.Now().UnixNano())

	var baseline []physics.Cube
	var current []physics.Cube

	file, err := os.Open(flag.Arg(0))
	check(err)

	dec := gob.NewDecoder(file)
	dec.Decode(&current)
	dec.Decode(&baseline)

	minimal := 1 << 10

	items := []int{}
	for i := range current {
		cube, base := &current[i], &baseline[i]
		if *cube != *base {
			items = append(items, i)
		}
	}

	items6 := physics.Index6(items, len(current))
	cur6 := physics.Delta6(baseline, current)
	max := uint64(0)
	for _, i := range items6 {
		ext := uint64(bit.ZEncode(int64(cur6(i))))
		if max < ext {
			max = ext
		}
	}

	nbits := bit.ScanRight(max) + 1

	for i := 0; i < *tries; i += 1 {
		menc, desc := RandomTree(nbits)
		enc := arith.NewEncoder()

		for _, i := range items {
			cube := &current[i]
			menc.Encode(enc, uint(cube.Interacting^1))
		}

		for _, i := range items {
			cube, base := &current[i], &baseline[i]
			v := uint(cube.Largest ^ base.Largest)
			menc.Encode(enc, v&1)
			menc.Encode(enc, v>>1)
		}

		enc.Close()

		if len(enc.Bytes()) < minimal {
			fmt.Printf("%6d %5d   - %s\n", i, len(enc.Bytes()), desc)
			minimal = len(enc.Bytes())
		}
	}
}