如何計出浮动平均數

是 否 +2 论坛币

k人 参与回答

经管之家送您一份

应届毕业生专属福利!

求职就业群

赵安豆老师微信：zhaoandou666

经管之家联合CDA

送您一个全额奖学金名额~ !

立即领取

感谢您参与论坛问题回答

经管之家送您两个论坛币！

+2 论坛币

各位大大好,

假如 df 有以下数据,

index	name	amount
1	A	10
2	B	14
3	C	3
4	A	4
5	A	15
6	C	9
7	B	12
8	B	8
8	C	6
9	A	7
10	B	8
11	C	10
12	A	13
13	B	14
14	C	8
15	A	12
16	C	9
17	A	6
18	C	10
19	A	3

df <- data.frame(index = 1:20, name = c("A", "B", "C", "A", "A", "C", "B", "C", "A", "B", "C", "A", "A", "A", "C", "B", "C", "A", "B", "C"), amount = c(10,14,3,4,15,9,12,6,7,8,10,13,12,6,8,8,9,3,14,10))

index	name	amount	last3avg
1	A	10	NA
2	B	14	NA
3	C	3	NA
4	A	4	NA
5	A	15	9.667
6	C	9	NA
7	B	12	NA
8	B	8	11.333
8	C	6	6.000
9	A	7	8.667
10	B	8	9.333
11	C	10	8.333
12	A	13	11.667
13	B	14	10.000
14	C	8	8.000
15	A	12	10.667
16	C	9	9.000
17	A	6	10.333
18	C	10	9.000
19	A	3	7.000

如何計出, A,B,C "近三次"平均amount, 不足3次出na值

扫码加我 拉你入群

请注明：姓名-公司-职位

以便审核进群资格，未注明则拒绝

分享0 收藏0 回帖

关键词：amount Index name AMO eam

这个是 moving average 的内容吧

install.packages('TTR')
library(dplyr)
library(TTR)

df <- data.frame(index = 1:20, name = c("A", "B", "C", "A", "A", "C", "B", "C", "A", "B", "C", "A", "A", "A", "C", "B", "C", "A", "B", "C"), amount = c(10,14,3,4,15,9,12,6,7,8,10,13,12,6,8,8,9,3,14,10))

all_data=data.frame()
for (a in unique(df$name)){
data=df%>%filter(name==a)%>%mutate(last3avg=runMean(amount, n = 3, cumulative = FALSE))  
all_data=rbind(data,all_data)
}

all_data=all_data%>%arrange(index)
all_data

感謝 rainningpoet 兄的回答, 效果是我想要的, 謝謝.

另外, 亦多謝jinkelazzz兄在EXCEL 的見解,
我提問沒有說清楚是用 R, 真不好意思, 但十分多謝熱心的前輩

rainningpoet 兄,

df <- data.frame(index = 1:20, name = c("A", "B", "C", "A", "A", "C", "B", "C", "A", "B", "C", "A", "A", "A", "C", "B", "C", "A", "B", "D"), amount = c(10,14,3,4,15,9,12,6,7,8,10,13,12,6,8,8,9,3,14,10))

如果我name第20項, 改為"D", 你的公式就沒法远作了, 請問有其他解決方法嗎 ?

因为D不够3位。

library(dplyr)
library(TTR)

df <- data.frame(index = 1:20, name = c("A", "B", "C", "A", "A", "C", "B", "C", "A", "B", "C", "A", "A", "A", "C", "B", "C", "A", "B", "D"),
                 amount = c(10,14,3,4,15,9,12,6,7,8,10,13,12,6,8,8,9,3,14,10))


all_data=data.frame()
for (a in unique(df$name)){
  if (nrow(df%>%filter(name==a))<3){
  data=df%>%filter(name==a)%>%mutate(last3avg=NA)
  }else{
  data=df%>%filter(name==a)%>%mutate(last3avg=runMean(amount, n = 3, cumulative = FALSE))
  }
  all_data=rbind(data,all_data)
}

all_data=all_data%>%arrange(index)
all_data