From d151b0a7ecbda97b13abfdb5cfdc61f8b40ff0c5 Mon Sep 17 00:00:00 2001
From: wangfeng <wangfengxy@sina.cn>
Date: Thu, 9 Feb 2023 15:40:04 +0800
Subject: [PATCH] =?UTF-8?q?#I6CYP1=20=E5=AE=9E=E7=8E=B0=E4=BA=86LAST?=
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---
 formula/README.md    |  2 +-
 formula/last.go      | 35 +++++++++++++++++++++++++++++++++++
 formula/last_test.go | 14 ++++++++++++++
 3 files changed, 50 insertions(+), 1 deletion(-)
 create mode 100644 formula/last.go
 create mode 100644 formula/last_test.go

diff --git a/formula/README.md b/formula/README.md
index dc1bf4e..63c49ab 100644
--- a/formula/README.md
+++ b/formula/README.md
@@ -30,7 +30,7 @@ formula
 | 0   | AVEDEV        | 平均绝对差,序列与其平均值的绝对差的平均值                              | AVEDEV(CLOSE,5)                   | [X]  | [X]  |
 | 0   | SLOPE         | S序列N周期回线性回归斜率                                      | SLOPE(CLOSE,5)                    | [X]  | [X]  |
 | 0   | FORCAST       | S序列N周期回线性回归后的预测值                                   | FORCAST(CLOSE,5)                  | [X]  | [X]  |
-| 0   | LAST          | 从前A日到前B日一直满足S条件,要求A>B & A>0 & B>=0                 | LAST(CLOSE>REF(CLOSE,1),LOW,HIGH) | [X]  | [X]  |
+| 0   | LAST          | 从前A日到前B日一直满足S条件,要求A>B & A>0 & B>=0                 | LAST(CLOSE>REF(CLOSE,1),LOW,HIGH) | [√]  | [√x] |
 | 1   | COUNT         | COUNT(CLOSE>O,N),最近N天满足S的天数True的天数                 | COUNT(CLOSE>LOW,5)                | [√]  | [√]  |
 | 1   | EVERY         | EVERY(CLOSE>O,5),最近N天是否都是True                      | EVERY(CLOSE>LOW,5)                | [X]  | [X]  |
 | 1   | EXIST         | EXIST(CLOSE>O,5),最近N天是否都是True                      | EXIST(CLOSE>LOW,5)                | [X]  | [X]  |
diff --git a/formula/last.go b/formula/last.go
new file mode 100644
index 0000000..62762f3
--- /dev/null
+++ b/formula/last.go
@@ -0,0 +1,35 @@
+package formula
+
+import (
+	"gitee.com/quant1x/pandas"
+	"gitee.com/quant1x/pandas/stat"
+)
+
+// LAST LAST(X,A,B):持续存在.
+//
+//	A 支持序列化, B不支持
+//	例如:
+//	LAST(CLOSE>OPEN,10,5)
+//	表示从前10日到前5日内一直阳线
+//	若A为0,表示从第一天开始,B为0,表示到最后日止
+func LAST(X pandas.Series, A, B int) pandas.Series {
+	s := X.Rolling(A + 1).Apply(func(S pandas.Series, N stat.DType) stat.DType {
+		s := S.DTypes()
+		s = stat.Reverse(s)
+		T := s[B:]
+		n := len(T)
+		for _, v := range T {
+			if v != 0 {
+				n--
+			}
+		}
+		if n == 0 {
+			return 1
+		} else {
+			return 0
+		}
+	})
+	d := s.Values().([]stat.DType)
+	stat.Fill(d, 1, true)
+	return s
+}
diff --git a/formula/last_test.go b/formula/last_test.go
new file mode 100644
index 0000000..9e64bc2
--- /dev/null
+++ b/formula/last_test.go
@@ -0,0 +1,14 @@
+package formula
+
+import (
+	"fmt"
+	"gitee.com/quant1x/pandas"
+	"testing"
+)
+
+func TestLAST(t *testing.T) {
+	f0 := []float64{1, 2, 3, 4, 5, 6, 0, 8, 9, 10, 11, 12}
+	i0 := CompareGt(f0, 10)
+	s0 := pandas.NewSeriesWithoutType("f0", i0)
+	fmt.Println(LAST(s0, 10, 5))
+}
-- 
Gitee