diff --git a/formula/README.md b/formula/README.md
index e576b578f2b827702f0d8868e6c38d7f9d815492..e4e9976f78ea53c8358deb831c9dca11a0efa00b 100644
--- a/formula/README.md
+++ b/formula/README.md
@@ -36,7 +36,7 @@ formula
 | 1   | FILTER        | FILTER函数，S满足条件后，将其后N周期内的数据置为0                      | FILTER(CLOSE>LOW,5)               | [X]  | [X]  |
 | 1   | BARSLAST      | 上一次条件成立到当前的周期数                                     | BARSLAST(X)                       | [√]  | [√]  |
 | 1   | BARSLASTCOUNT | 统计连续满足S条件的周期数                                      | BARSLASTCOUNT(X)                  | [X]  | [X]  |
-| 1   | BARSSINCEN    | N周期内第一次S条件成立到现在的周期数                                | BARSSINCEN(S,N)                   | [X]  | [X]  |
+| 1   | BARSSINCEN    | N周期内第一次S条件成立到现在的周期数                                | BARSSINCEN(S,N)                   | [√]  | [√]  |
 | 1   | CROSS         | 判断向上金叉穿越,两个序列互换就是判断向下死叉穿越                          | CROSS(MA(C,5),MA(C,10))           | [X]  | [X]  |
 | 1   | LONGCROSS     | 两条线维持一定周期后交叉,S1在N周期内都小于S2,本周期从S1下方向上穿过S2时返回1,否则返回0 | LONGCROSS(MA(C,5),MA(C,10),5)     | [X]  | [X]  |
 | 1   | VALUEWHEN     | 当S条件成立时,取X的当前值,否则取VALUEWHEN的上个成立时的X值               | VALUEWHEN(S,X)                    | [X]  | [X]  |
diff --git a/formula/barssincen.go b/formula/barssincen.go
new file mode 100644
index 0000000000000000000000000000000000000000..decbd3ee8c586d3428265eed5a6dab0239df2ec0
--- /dev/null
+++ b/formula/barssincen.go
@@ -0,0 +1,26 @@
+package formula
+
+import (
+	"gitee.com/quant1x/pandas"
+	"gitee.com/quant1x/pandas/stat"
+)
+
+// BARSSINCEN N周期内第一次S条件成立到现在的周期数,N为常量
+func BARSSINCEN(S pandas.Series, N any) []stat.Int {
+	ret := S.Rolling(N).Apply(func(X pandas.Series, M stat.DType) stat.DType {
+		x := X.DTypes()
+		n := int(M)
+		argMax := stat.ArgMax(x)
+		r := 0
+		if argMax != 0 || x[0] != 0 {
+			r = n - 1 - argMax
+
+		} else {
+			r = 0
+		}
+		return stat.DType(r)
+	})
+	r1 := ret.FillNa(0, true)
+	r2 := r1.AsInt()
+	return r2
+}
diff --git a/formula/barssincen_test.go b/formula/barssincen_test.go
new file mode 100644
index 0000000000000000000000000000000000000000..918707982b692dc60ceb030e989efac3ec361714
--- /dev/null
+++ b/formula/barssincen_test.go
@@ -0,0 +1,25 @@
+package formula
+
+import (
+	"fmt"
+	"gitee.com/quant1x/pandas"
+	"gitee.com/quant1x/pandas/stat"
+	"testing"
+)
+
+func TestBARSSINCEN(t *testing.T) {
+	f1 := []int64{1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4}
+	s1 := pandas.NewSeries(pandas.SERIES_TYPE_DTYPE, "", f1)
+	df := pandas.NewDataFrame(s1)
+	fmt.Println(df)
+
+	b1 := s1.Logic(func(idx int, v any) bool {
+		f := v.(stat.DType)
+		return f > 3
+	})
+	df = df.Join(pandas.NewSeries(pandas.SERIES_TYPE_BOOL, "r", b1))
+	fmt.Println(df)
+	//c1 = df > 3
+	r1 := BARSSINCEN(df.Col("r"), 4)
+	fmt.Println(r1)
+}
diff --git a/generic.go b/generic.go
index d41998298ba07d6f0629847c58c60711b60f9fde..823a7ec873b64bf401d6f74d088923866a390199 100644
--- a/generic.go
+++ b/generic.go
@@ -161,6 +161,12 @@ func (self *NDFrame) DTypes() []stat.DType {
 	return stat.Slice2DType(self.Values())
 }
 
+// AsInt 强制转换成整型
+func (self *NDFrame) AsInt() []stat.Int {
+	values := self.DTypes()
+	return stat.DType2Int(values)
+}
+
 func (self *NDFrame) Empty() Series {
 	var frame NDFrame
 	if self.type_ == SERIES_TYPE_STRING {
@@ -311,7 +317,7 @@ func (self *NDFrame) Std() stat.DType {
 	return stdDev
 }
 
-func (self *NDFrame) FillNa(v any, inplace bool) {
+func (self *NDFrame) FillNa(v any, inplace bool) Series {
 	values := self.Values()
 	switch rows := values.(type) {
 	case []string:
@@ -339,4 +345,5 @@ func (self *NDFrame) FillNa(v any, inplace bool) {
 			}
 		}
 	}
+	return self
 }
diff --git a/generic_apply.go b/generic_apply.go
index b311406490e54151a93930794b2e687b0a921db6..6faf9f37e93197b29ce9286910baa3f890e548fa 100644
--- a/generic_apply.go
+++ b/generic_apply.go
@@ -22,3 +22,26 @@ func (self *NDFrame) Apply(f func(idx int, v any)) {
 		// 其它类型忽略
 	}
 }
+
+func (self *NDFrame) Logic(f func(idx int, v any) bool) []bool {
+	x := make([]bool, self.Len())
+	vv := reflect.ValueOf(self.values)
+	vk := vv.Kind()
+	switch vk {
+	case reflect.Invalid: // {interface} nil
+		//series.assign(idx, size, Nil2Float64)
+	case reflect.Slice: // 切片, 不定长
+		for i := 0; i < vv.Len(); i++ {
+			tv := vv.Index(i).Interface()
+			x[i] = f(i, tv)
+		}
+	case reflect.Array: // 数组, 定长
+		for i := 0; i < vv.Len(); i++ {
+			tv := vv.Index(i).Interface()
+			x[i] = f(i, tv)
+		}
+	default:
+		// 其它类型忽略
+	}
+	return x
+}
diff --git a/generic_rolling.go b/generic_rolling.go
index 8c0494d5ad9cd99b97728157b124e1330d69edeb..caf86d38c7c263c53821ca9862b53375ebcc851d 100644
--- a/generic_rolling.go
+++ b/generic_rolling.go
@@ -48,8 +48,7 @@ func (r RollingAndExpandingMixin) getBlocks() (blocks []Series) {
 	return
 }
 
-// Apply 接受一个回调
-func (r RollingAndExpandingMixin) Apply(f func(S Series, N stat.DType) stat.DType) (s Series) {
+func (r RollingAndExpandingMixin) Apply_v1(f func(S Series, N stat.DType) stat.DType) (s Series) {
 	s = r.series.Empty()
 	for i, block := range r.getBlocks() {
 		if block.Len() == 0 {
@@ -61,3 +60,18 @@ func (r RollingAndExpandingMixin) Apply(f func(S Series, N stat.DType) stat.DTyp
 	}
 	return
 }
+
+// Apply 接受一个回调
+func (r RollingAndExpandingMixin) Apply(f func(S Series, N stat.DType) stat.DType) (s Series) {
+	values := make([]stat.DType, r.series.Len())
+	for i, block := range r.getBlocks() {
+		if block.Len() == 0 {
+			values[i] = stat.DTypeNaN
+			continue
+		}
+		v := f(block, r.window[i])
+		values[i] = v
+	}
+	s = NewSeries(SERIES_TYPE_DTYPE, r.series.Name(), values)
+	return
+}
diff --git a/series.go b/series.go
index 95b462028baf25dce17adce3ae2c4ddafcbdba64..0bbd2a139fb34b3fc260f8aa5a9518b41c9e9158 100644
--- a/series.go
+++ b/series.go
@@ -43,6 +43,8 @@ type Series interface {
 	Float() []float32
 	// DTypes 强制转[]stat.DType
 	DTypes() []stat.DType
+	// 强制转换成整型
+	AsInt() []stat.Int
 
 	// sort.Interface
 
@@ -76,7 +78,7 @@ type Series interface {
 	// StdDev calculates the standard deviation of a series
 	StdDev() stat.DType
 	// FillNa Fill NA/NaN values using the specified method.
-	FillNa(v any, inplace bool)
+	FillNa(v any, inplace bool) Series
 	// Max 找出最大值
 	Max() any
 	// Min 找出最小值
@@ -87,6 +89,8 @@ type Series interface {
 	Append(values ...any)
 	// Apply 接受一个回调函数
 	Apply(f func(idx int, v any))
+	// Logic 逻辑处理
+	Logic(f func(idx int, v any) bool) []bool
 	// Diff 元素的第一个离散差
 	Diff(param any) (s Series)
 	// Ref 引用其它周期的数据
diff --git a/series_bool.go b/series_bool.go
index 49d809184eabf74526f5203ffa67c91a90f7bf73..bba6d2e24ce35d86b6dccebdb253f8e0979e9a9a 100644
--- a/series_bool.go
+++ b/series_bool.go
@@ -161,7 +161,7 @@ func (self *SeriesBool) StdDev() float64 {
 }
 
 // FillNa bool类型不可能在导入series还是NaN
-func (self *SeriesBool) FillNa(v any, inplace bool) {
+func (self *SeriesBool) FillNa(v any, inplace bool) Series {
 	//values := self.Values()
 	//switch rows := values.(type) {
 	//case []bool:
@@ -171,4 +171,5 @@ func (self *SeriesBool) FillNa(v any, inplace bool) {
 	//		}
 	//	}
 	//}
+	return self
 }
diff --git a/series_float64.go b/series_float64.go
index cf18de5d0740235ebd23855df89463c0d89925a1..6808b40f12c76fb4daa94b8ab0111d650d3bab7b 100644
--- a/series_float64.go
+++ b/series_float64.go
@@ -221,7 +221,7 @@ func (self *SeriesFloat64) StdDev() float64 {
 	return stdDev
 }
 
-func (self *SeriesFloat64) FillNa(v any, inplace bool) {
+func (self *SeriesFloat64) FillNa(v any, inplace bool) Series {
 	values := self.Values()
 	switch rows := values.(type) {
 	case []float64:
@@ -231,4 +231,5 @@ func (self *SeriesFloat64) FillNa(v any, inplace bool) {
 			}
 		}
 	}
+	return self
 }
diff --git a/series_int64.go b/series_int64.go
index d16c9266b00402874aa1243b41afcf8d8fb0359a..6ed732baf9dca9af6b0e29cc126c50f8e3def4a8 100644
--- a/series_int64.go
+++ b/series_int64.go
@@ -180,7 +180,7 @@ func (self *SeriesInt64) StdDev() float64 {
 }
 
 // FillNa int64没有NaN
-func (self *SeriesInt64) FillNa(v any, inplace bool) {
+func (self *SeriesInt64) FillNa(v any, inplace bool) Series {
 	values := self.Values()
 	switch rows := values.(type) {
 	case []int64:
@@ -190,4 +190,5 @@ func (self *SeriesInt64) FillNa(v any, inplace bool) {
 			}
 		}
 	}
+	return self
 }
diff --git a/series_xstring.go b/series_xstring.go
index eee9a6dd9363639c632188392deef4c14a594747..6d653963f892a3d5cf74aaead111ab036bf18c3b 100644
--- a/series_xstring.go
+++ b/series_xstring.go
@@ -165,7 +165,7 @@ func (self *SeriesString) StdDev() float64 {
 	panic("implement me")
 }
 
-func (self *SeriesString) FillNa(v any, inplace bool) {
+func (self *SeriesString) FillNa(v any, inplace bool) Series {
 	values := self.Values()
 	switch rows := values.(type) {
 	case []string:
@@ -175,4 +175,6 @@ func (self *SeriesString) FillNa(v any, inplace bool) {
 			}
 		}
 	}
+
+	return self
 }
diff --git a/stat/argmax.go b/stat/argmax.go
new file mode 100644
index 0000000000000000000000000000000000000000..27b4029a4f1760972b98c4d5e5860f1434648bf2
--- /dev/null
+++ b/stat/argmax.go
@@ -0,0 +1,33 @@
+package stat
+
+import (
+	"github.com/viterin/vek"
+	"github.com/viterin/vek/vek32"
+)
+
+// ArgMax Returns the indices of the maximum values along an axis.
+// 返回轴上最大值的索引
+func ArgMax[T Number](v []T) int {
+	var vv any = v
+	switch values := vv.(type) {
+	case []float32:
+		return vek32.ArgMax(values)
+	case []float64:
+		return vek.ArgMax(values)
+	default:
+		return __arg_max(v)
+	}
+
+}
+
+func __arg_max[T Number](x []T) int {
+	max := x[0]
+	idx := 0
+	for i, v := range x[1:] {
+		if v > max {
+			max = v
+			idx = 1 + i
+		}
+	}
+	return idx
+}
diff --git a/stat/argmax_test.go b/stat/argmax_test.go
new file mode 100644
index 0000000000000000000000000000000000000000..c7800019b975e866a60b826f92fd8dcbda0e1be1
--- /dev/null
+++ b/stat/argmax_test.go
@@ -0,0 +1,15 @@
+package stat
+
+import (
+	"fmt"
+	"testing"
+)
+
+func TestArgMax(t *testing.T) {
+	n1 := []float32{1.1, 2.2, 1.3, 1.4}
+	n2 := []float64{1.2, 1.2, 3.3}
+	n3 := []int64{11, 12, 33}
+	fmt.Println(ArgMax(n1))
+	fmt.Println(ArgMax(n2))
+	fmt.Println(ArgMax(n3))
+}
diff --git a/stat/argmin.go b/stat/argmin.go
new file mode 100644
index 0000000000000000000000000000000000000000..b9b8b0ff02c0d0a6c12876de768ae4c16048afb6
--- /dev/null
+++ b/stat/argmin.go
@@ -0,0 +1,33 @@
+package stat
+
+import (
+	"github.com/viterin/vek"
+	"github.com/viterin/vek/vek32"
+)
+
+// ArgMin Returns the indices of the minimum values along an axis.
+// 返回轴上最小值的索引
+func ArgMin[T Number](v []T) int {
+	var vv any = v
+	switch values := vv.(type) {
+	case []float32:
+		return vek32.ArgMin(values)
+	case []float64:
+		return vek.ArgMin(values)
+	default:
+		return __arg_min(v)
+	}
+
+}
+
+func __arg_min[T Number](x []T) int {
+	min := x[0]
+	idx := 0
+	for i, v := range x[1:] {
+		if v < min {
+			min = v
+			idx = 1 + i
+		}
+	}
+	return idx
+}
diff --git a/stat/argmin_test.go b/stat/argmin_test.go
new file mode 100644
index 0000000000000000000000000000000000000000..1f61bb721328fe37ed42e84a8130c11c4b19f68a
--- /dev/null
+++ b/stat/argmin_test.go
@@ -0,0 +1,15 @@
+package stat
+
+import (
+	"fmt"
+	"testing"
+)
+
+func TestArgMin(t *testing.T) {
+	n1 := []float32{1.1, 2.2, 1.3, 1.4}
+	n2 := []float64{1.2, 1.2, 0.3}
+	n3 := []int64{11, 12, 33}
+	fmt.Println(ArgMin(n1))
+	fmt.Println(ArgMin(n2))
+	fmt.Println(ArgMin(n3))
+}
diff --git a/stat/median.go b/stat/median.go
new file mode 100644
index 0000000000000000000000000000000000000000..6be0964b85e2b17df0c9ae98b5d8ace58546128d
--- /dev/null
+++ b/stat/median.go
@@ -0,0 +1,21 @@
+package stat
+
+// Median returns median value of series.
+// Linear interpolation is used for odd length.
+// TODO:未加验证
+func Median[T StatType](values []T) DType {
+	if len(values) == 0 {
+		return DTypeNaN
+	}
+
+	if len(values) == 1 {
+		return DType(0)
+	}
+
+	if len(values)%2 == 0 {
+		i := len(values) / 2
+		return DType(values[i-1]+values[i]) / 2
+	}
+
+	return DType(values[len(values)/2])
+}
diff --git a/stat/type_dtype.go b/stat/type_dtype.go
index c87da202eb76630cac9682759c334ceb22b81f28..26bbf5e6a27997e6f1ab1d6d319424581861c420 100644
--- a/stat/type_dtype.go
+++ b/stat/type_dtype.go
@@ -1,6 +1,11 @@
 package stat
 
+import (
+	"github.com/viterin/vek"
+)
+
 type DType = float64
+type Int = int32
 
 // DTypeIsNaN 判断DType是否NaN
 func DTypeIsNaN(d DType) bool {
@@ -16,3 +21,8 @@ func Slice2DType(v any) []DType {
 func Any2DType(v any) DType {
 	return AnyToFloat64(v)
 }
+
+// DType切片转int32切片
+func DType2Int(d []DType) []Int {
+	return vek.ToInt32(d)
+}