Question

这是我的代码：

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", "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)){
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)

这就是错误：

mutate_impl（.data，dots）中的错误：评估错误：n = 3超出有效范围：[1,1]。

为什么会发生此错误以及如何解决？

Answer 1

尝试运行：

runMean(df %>% filter(name == "A") %>% select(amount), n = 3, cumulative = FALSE)

现在，试试这个：

runMean(df %>% filter(name == "D") %>% select(amount), n = 3, cumulative = FALSE)

区别在于D只有一个条目，因此n = 3毫无意义。

编辑以解决以下评论

为避免错误，您可以进行过滤以确保每个name始终至少有3个实例。例如，

df %<>% group_by(name) %>% filter(n() >= 3) %>% ungroup

RunMean和mutate的评估错误

1 个答案: