Question

我正在尝试获取与某种特定颜色关联的观察总数。

Date <- c("2017-01-01","2017-01-01","2017-01-02","2017-01-03","2017-01-03","2017-01-03","2017-01-03","2017-01-04","2017-01-04","2017-01-05")

Factor<-c("red", "blue", "green", "red", "red", "green", "green", "blue", "blue", "green")

每个因素的不同表。他们每年的每一天都应该有一行，并包含观察的总数。

green <-  table(cut(ex$Date[which(ex$Factor=="green")], 'day'))

它以某种方式起作用，但并不完美。如果没有对01.01.2017的观察，而对02.01.2017的观察，则它将以02.01.2017开头。数据集为一年。相同的问题会在年底出现（例如，2017年12月31日，2017年12月30日，...被省略）。

2017-01-02   1
2017-01-03   2
2017-01-04   0
2017-01-05   1

有人知道我该如何解决吗？

Answer 1

这是一个使用aggregate的基本R选项：

df <- data.frame(Date, Color, stringsAsFactors=FALSE)
aggregate(df$Color, by=list(Date=df$Date), FUN=function(x) { sum(x=="green") })

        Date x
1 2017-01-01 0
2 2017-01-02 1
3 2017-01-03 2
4 2017-01-04 0
5 2017-01-05 1

数据：

Date <- c("2017-01-01","2017-01-01","2017-01-02","2017-01-03","2017-01-03","2017-01-03",
    "2017-01-03","2017-01-04","2017-01-04","2017-01-05")
Color <- c("red", "blue", "green", "red", "red", "green", "green", "blue", "blue", "green")

按天省略在年初和年末的日期

1 个答案: