R使用前一行值和条件填写NA
我需要用前一行值填充NA行,但仅在不更改条件之前。 作为一周中几天、膳食和价格的简单示例:R使用前一行值和条件填写NA,r,na,R,Na,我需要用前一行值填充NA行,但仅在不更改条件之前。 作为一周中几天、膳食和价格的简单示例: Day = c("Mon", "Tues", "Wed", "Thus", "Fri", "Sat","Sun","Mon", "Tues", "Wed", "Thus", "Fri", "Sat","Sun") Meal = c("B","B","B","B","B","D","D","D","D","L","L", "L","L","L") Price = c(NA, 20, NA
Day = c("Mon", "Tues", "Wed", "Thus", "Fri", "Sat","Sun","Mon", "Tues",
"Wed", "Thus", "Fri", "Sat","Sun")
Meal = c("B","B","B","B","B","D","D","D","D","L","L", "L","L","L")
Price = c(NA, 20, NA,NA,NA,NA,NA,15,NA,NA,10,10,NA,10)
df = data.frame(Meal,Day ,Price )
df
Meal Day Price
1 B Mon NA
2 B Tues 20
3 B Wed NA
4 B Thus NA
5 B Fri NA
6 D Sat NA
7 D Sun NA
8 D Mon 15
9 D Tues NA
10 L Wed NA
11 L Thus 10
12 L Fri 10
13 L Sat NA
14 L Sun 10
我需要在NA中填写上一份,但只填写一周内相同的膳食类型
我试过了
na.locf(df, fromLast = TRUE)
Meal Day Price
1 B Mon 20
2 B Tues 20
3 B Wed 15
4 B Thus 15
5 B Fri 15
6 D Sat 15
7 D Sun 15
8 D Mon 15
9 D Tues 10
10 L Wed 10
11 L Thus 10
12 L Fri 10
13 L Sat 10
14 L Sun 10
这是错误的,因为与膳食类型重叠。
数据应如下所示:
Meal Day Price
1 B Mon 20
2 B Tues 20
3 B Wed 20
4 B Thus 20
5 B Fri 20
6 D Sat 15
7 D Sun 15
8 D Mon 15
9 D Tues 15
10 L Wed 10
11 L Thus 10
12 L Fri 10
13 L Sat 10
14 L Sun 10
非常感谢您可以试试
library(zoo)
library(dplyr)
df %>%
group_by(Meal) %>%
mutate(Price= ifelse(any(!is.na(Price)), na.locf(na.locf(Price,
fromLast=TRUE, na.rm=FALSE)), NA_real_))
# Meal Day Price
#1 B Mon 20
#2 B Tues 20
#3 B Wed 20
#4 B Thus 20
#5 B Fri 20
#6 D Sat 15
#7 D Sun 15
#8 D Mon 15
#9 D Tues 15
#10 L Wed 10
#11 L Thus 10
#12 L Fri 10
#13 L Sat 10
#14 L Sun 10
另一个选项使用
data.table
library(data.table)
library(xts)
dt <- data.table(df)
dt[, Price := na.locf(Price, fromLast = TRUE), by = Meal]
库(data.table)
图书馆(xts)
dt我使用此选项收到警告消息,尽管它有效。我尝试了此解决方案,也收到了警告,但结果看起来不错。@akrun&@ichester-是的,我也收到了警告,不知道为什么说实话…akrun-我从您以前的data.table()
答案中也收到了类似的警告。@Chase Yes,它确实显示了我的数据。表解决方案也是如此,我的解决方案也不正确,因为每顿饭都有多个非NA值,虽然这个例子很简单,但我觉得每顿饭都会有不同的非NA值,此外,我仍然不确定数据集是否每顿饭有多周。我逐字尝试了这段代码,收到一条错误消息,上面说:na.locf中的错误(Price,fromLast=TRUE):未使用的参数(fromLast=TRUE)
如果每顿饭的“Day”列都有重复项,即每顿饭有多周,该怎么办?条件是在“Mon”还是“Sun”上重置的?我在样本数据上测试了这个解决方案,效果很好。如果我在我的数据(700万行)上使用它,它会出现以下错误:错误:大小不兼容(0),预期为39712(组大小)或1个字符df%>%groupby(餐)%%>%mutate(Price=ifelse(any(!is.na(Price))、na.locf(na.locf(Price,fromLast=TRUE,na.rm=FALSE))、na\u real\code>