将星期数转换为日期 [英] Convert week number to date

问题描述

我在R中有一个数据框，其中有要转换为日期的一年中的星期.我知道我必须选择一年中的一天，因此我将这些值固定为2014和1.将其转换为日期似乎很简单:

I have a data frame in R with the week of the year that I would like to convert to a date. I know I have to pick a year and a day of the week so I am fixing those values at 2014 and 1. Converting this to a date seems simple:

as.Date(paste(2014,df$Week,1,sep=""),"%Y%U%u")

但是，仅当Week大于9时，此代码才有效.Week 1-9返回NA.如果将星期更改为01,02,03 ...，它仍然返回NA.

But this code only works if week is greater than 9. Week 1 - 9 returns NA. If I change the week to 01,02,03... it still returns NA.

有人看到我想念的东西吗?

Anyone see what I am missing?

推荐答案

as.Date调用1到9作为NA，因为它期望星期数为两位数，并且无法正确解析.

as.Date is calling the 1 to 9 as NA as it is expects two digits for the week number and can't properly parse it.

要修复此问题，请添加一些内容-拆分内容:

To fix it, add in some - to split things up:

as.Date(paste(2014, df$Week, 1, sep="-"), "%Y-%U-%u")

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