使用seq()创建规则的日期时间序列(POSIXct) [英] Create a regular sequence of date-times (POSIXct) using seq()

问题描述

我的目标是创建一个给定起点，终点和增量(15分钟，1小时，1天)的POSIXct时间戳向量.我希望可以为此使用 seq ，但是在数字和POSIXct表示之间进行转换时遇到问题:

My goal is to create a vector of POSIXct time stamps given a start, an end and a delta (15min, 1hour, 1day). I hoped I could use seq for this, but I have a problem converting between the numeric and POSIXct representation:

now <- Sys.time()
now
# [1] "2012-01-19 10:30:39 CET"
as.POSIXct(as.double(now), origin="1970-01-01", tz="CET")
# [1] "2012-01-19 09:30:39 CET"
as.POSIXct(as.double(now), origin=as.POSIXct("1970-01-01", tz="CET"), tz="CET")
# [1] "2012-01-19 09:30:39 CET"

此转换过程中浪费了一个小时.我在做什么错了?

One hour gets lost during this conversion. What am I doing wrong?

推荐答案

对于超类为"POSIXt" 的对象，有一个 seq()方法"POSIXlt" 和"POSIXct" 类的集合.因此，您无需进行任何转换.

There is a seq() method for objects of class "POSIXt" which is the super class of the "POSIXlt" and "POSIXct" classes. As such you don't need to do any conversion.

> now <- Sys.time()
> tseq <- seq(from = now, length.out = 100, by = "mins")
> length(tseq)
[1] 100
> head(tseq)
[1] "2012-01-19 10:52:38 GMT" "2012-01-19 10:53:38 GMT"
[3] "2012-01-19 10:54:38 GMT" "2012-01-19 10:55:38 GMT"
[5] "2012-01-19 10:56:38 GMT" "2012-01-19 10:57:38 GMT"

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