用R格式化日期以仅显示年份

Question

我在R上有个“因数”类的日期。我想从数据中提取年份。请指教

示例数据：

S No. Customer Month           amount
1       A       01-01-2020      1500
2       B       23-02-2020      2000
3       C       15-03-2020      2500

Answer 1

data$Month <- as.character(data$Month) data$Month <- as.Date(data$Month,"%d-%m-%Y") data$Year <- year(data$Month)

Answer 2

尝试一下：

df <- read.table(text="S 'No. Customer' Month           amount
1       A       01-01-2020      1500
2       B       23-02-2020      2000
3       C       15-03-2020      2500", header = TRUE)

df$year <- format(as.Date(df$Month, "%d-%m-%Y"), "%Y")
df
#>   S No..Customer      Month amount year
#> 1 1            A 01-01-2020   1500 2020
#> 2 2            B 23-02-2020   2000 2020
#> 3 3            C 15-03-2020   2500 2020

^{由reprex package（v0.3.0）于2020-04-10创建}