xmaker: add depth ratio signal

pkg/strategy/xmaker/signal_book.go

@@ -29,6 +29,10 @@ type OrderBookBestPriceVolumeSignal struct {
 	book   *types.StreamOrderBook
 }
 
+func (s *OrderBookBestPriceVolumeSignal) BindStreamBook(book *types.StreamOrderBook) {
+	s.book = book
+}
+
 func (s *OrderBookBestPriceVolumeSignal) Bind(ctx context.Context, session *bbgo.ExchangeSession, symbol string) error {
 	if s.book == nil {
 		return errors.New("s.book can not be nil")

pkg/strategy/xmaker/signal_depth.go

@@ -0,0 +1,80 @@
+package xmaker
+
+import (
+	"context"
+	"math"
+
+	"github.com/pkg/errors"
+	"github.com/prometheus/client_golang/prometheus"
+
+	"github.com/c9s/bbgo/pkg/bbgo"
+	"github.com/c9s/bbgo/pkg/fixedpoint"
+	"github.com/c9s/bbgo/pkg/types"
+)
+
+var depthRatioSignalMetrics = prometheus.NewGaugeVec(
+	prometheus.GaugeOpts{
+		Name: "xmaker_depth_ratio_signal",
+		Help: "",
+	}, []string{"symbol"})
+
+func init() {
+	prometheus.MustRegister(depthRatioSignalMetrics)
+}
+
+type DepthRatioSignal struct {
+	// PriceRange, 2% depth ratio means 2% price range from the mid price
+	PriceRange fixedpoint.Value `json:"priceRange"`
+	MinRatio   float64          `json:"minRatio"`
+
+	symbol string
+	book   *types.StreamOrderBook
+}
+
+func (s *DepthRatioSignal) BindStreamBook(book *types.StreamOrderBook) {
+	s.book = book
+}
+
+func (s *DepthRatioSignal) Bind(ctx context.Context, session *bbgo.ExchangeSession, symbol string) error {
+	if s.book == nil {
+		return errors.New("s.book can not be nil")
+	}
+
+	s.symbol = symbol
+	orderBookSignalMetrics.WithLabelValues(s.symbol).Set(0.0)
+	return nil
+}
+
+func (s *DepthRatioSignal) CalculateSignal(ctx context.Context) (float64, error) {
+	bid, ask, ok := s.book.BestBidAndAsk()
+	if !ok {
+		return 0.0, nil
+	}
+
+	midPrice := bid.Price.Add(ask.Price).Div(fixedpoint.Two)
+
+	asks := s.book.SideBook(types.SideTypeSell)
+	bids := s.book.SideBook(types.SideTypeBuy)
+
+	asksInRange := asks.InPriceRange(midPrice, types.SideTypeSell, s.PriceRange)
+	bidsInRange := bids.InPriceRange(midPrice, types.SideTypeBuy, s.PriceRange)
+
+	askDepthQuote := asksInRange.SumDepthInQuote()
+	bidDepthQuote := bidsInRange.SumDepthInQuote()
+
+	var signal = 0.0
+
+	depthRatio := bidDepthQuote.Div(askDepthQuote.Add(bidDepthQuote))
+
+	// convert ratio into -2.0 and 2.0
+	signal = depthRatio.Sub(fixedpoint.NewFromFloat(0.5)).Float64() * 4.0
+
+	// ignore noise
+	if math.Abs(signal) < s.MinRatio {
+		signal = 0.0
+	}
+
+	log.Infof("[DepthRatioSignal] %f bid/ask = %f/%f", signal, bidDepthQuote.Float64(), askDepthQuote.Float64())
+	depthRatioSignalMetrics.WithLabelValues(s.symbol).Set(signal)
+	return signal, nil
+}

pkg/strategy/xmaker/signal_depth_test.go

@@ -0,0 +1,113 @@
+package xmaker
+
+import (
+	"context"
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+
+	"github.com/c9s/bbgo/pkg/fixedpoint"
+	"github.com/c9s/bbgo/pkg/types"
+
+	. "github.com/c9s/bbgo/pkg/testing/testhelper"
+)
+
+func TestDepthRatioSignal_CalculateSignal(t *testing.T) {
+	type fields struct {
+		PriceRange fixedpoint.Value
+		MinRatio   float64
+		symbol     string
+		book       *types.StreamOrderBook
+	}
+	type args struct {
+		ctx        context.Context
+		bids, asks types.PriceVolumeSlice
+	}
+
+	tests := []struct {
+		name    string
+		fields  fields
+		args    args
+		want    float64
+		wantErr assert.ErrorAssertionFunc
+	}{
+		{
+			name: "test1",
+			fields: fields{
+				PriceRange: fixedpoint.NewFromFloat(0.02),
+				MinRatio:   0.01,
+				symbol:     "BTCUSDT",
+			},
+			args: args{
+				ctx: context.Background(),
+				asks: PriceVolumeSliceFromText(`
+					19310,1.0
+					19320,0.2
+					19330,0.3
+					19340,0.4
+					19350,0.5
+				`),
+				bids: PriceVolumeSliceFromText(`
+					19300,0.1
+					19290,0.2
+					19280,0.3
+					19270,0.4
+					19260,0.5
+				`),
+			},
+			want:    -0.4641,
+			wantErr: assert.NoError,
+		},
+		{
+			name: "normal",
+			fields: fields{
+				PriceRange: fixedpoint.NewFromFloat(0.02),
+				MinRatio:   0.01,
+				symbol:     "BTCUSDT",
+			},
+			args: args{
+				ctx: context.Background(),
+				asks: PriceVolumeSliceFromText(`
+					19310,0.1
+					19320,0.2
+					19330,0.3
+					19340,0.4
+					19350,0.5
+				`),
+				bids: PriceVolumeSliceFromText(`
+					19300,0.1
+					19290,0.2
+					19280,0.3
+					19270,0.4
+					19260,0.5
+				`),
+			},
+			want:    0,
+			wantErr: assert.NoError,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			s := &DepthRatioSignal{
+				PriceRange: tt.fields.PriceRange,
+				MinRatio:   tt.fields.MinRatio,
+				symbol:     tt.fields.symbol,
+				book:       types.NewStreamBook("BTCUSDT", types.ExchangeBinance),
+			}
+
+			s.book.Load(types.SliceOrderBook{
+				Symbol: "BTCUSDT",
+				Bids:   tt.args.bids,
+				Asks:   tt.args.asks,
+			})
+
+			got, err := s.CalculateSignal(tt.args.ctx)
+			if !tt.wantErr(t, err, fmt.Sprintf("CalculateSignal(%v)", tt.args.ctx)) {
+				return
+			}
+
+			assert.InDeltaf(t, tt.want, got, 0.001, "CalculateSignal(%v)", tt.args.ctx)
+		})
+	}
+}

pkg/strategy/xmaker/strategy.go

@@ -64,6 +64,7 @@ type SignalConfig struct {
 	Weight                   float64                         `json:"weight"`
 	BollingerBandTrendSignal *BollingerBandTrendSignal       `json:"bollingerBandTrend,omitempty"`
 	OrderBookBestPriceSignal *OrderBookBestPriceVolumeSignal `json:"orderBookBestPrice,omitempty"`
+	DepthRatioSignal         *DepthRatioSignal               `json:"depthRatio,omitempty"`
 	KLineShapeSignal         *KLineShapeSignal               `json:"klineShape,omitempty"`
 	TradeVolumeWindowSignal  *TradeVolumeWindowSignal        `json:"tradeVolumeWindow,omitempty"`
 }
@@ -390,6 +391,8 @@ func (s *Strategy) aggregateSignal(ctx context.Context) (float64, error) {
 		var err error
 		if signal.OrderBookBestPriceSignal != nil {
 			sig, err = signal.OrderBookBestPriceSignal.CalculateSignal(ctx)
+		} else if signal.DepthRatioSignal != nil {
+			sig, err = signal.DepthRatioSignal.CalculateSignal(ctx)
 		} else if signal.BollingerBandTrendSignal != nil {
 			sig, err = signal.BollingerBandTrendSignal.CalculateSignal(ctx)
 		} else if signal.TradeVolumeWindowSignal != nil {
@@ -1547,6 +1550,11 @@ func (s *Strategy) CrossRun(
 			if err := signalConfig.OrderBookBestPriceSignal.Bind(ctx, s.sourceSession, s.Symbol); err != nil {
 				return err
 			}
+		} else if signalConfig.DepthRatioSignal != nil {
+			signalConfig.DepthRatioSignal.book = s.sourceBook
+			if err := signalConfig.DepthRatioSignal.Bind(ctx, s.sourceSession, s.Symbol); err != nil {
+				return err
+			}
 		} else if signalConfig.BollingerBandTrendSignal != nil {
 			if err := signalConfig.BollingerBandTrendSignal.Bind(ctx, s.sourceSession, s.Symbol); err != nil {
 				return err

pkg/types/price_volume_slice.go

@@ -280,6 +280,28 @@ func (slice PriceVolumeSlice) AverageDepthPriceByQuote(requiredDepthInQuote fixe
 	return totalQuoteAmount.Div(totalQuantity)
 }
 
+func (slice PriceVolumeSlice) InPriceRange(midPrice fixedpoint.Value, side SideType, r fixedpoint.Value) (sub PriceVolumeSlice) {
+	switch side {
+	case SideTypeSell:
+		boundaryPrice := midPrice.Add(midPrice.Mul(r))
+		for _, pv := range slice {
+			if pv.Price.Compare(boundaryPrice) <= 0 {
+				sub = append(sub, pv)
+			}
+		}
+
+	case SideTypeBuy:
+		boundaryPrice := midPrice.Sub(midPrice.Mul(r))
+		for _, pv := range slice {
+			if pv.Price.Compare(boundaryPrice) >= 0 {
+				sub = append(sub, pv)
+			}
+		}
+	}
+
+	return sub
+}
+
 // AverageDepthPrice uses the required total quantity to calculate the corresponding price
 func (slice PriceVolumeSlice) AverageDepthPrice(requiredQuantity fixedpoint.Value) fixedpoint.Value {
 	// rest quantity