如何在 R 中将字符串转换为日期时间?
在本文中,我们将讨论如何在 R 编程语言中将字符串转换为日期时间。我们可以使用 POSIXct函数将字符串转换为 DateTime
Syntax: as.POSIXct(string, format=”%Y-%m-%d %H:%M:%S”, tz=”UTC”)
where
- string is the input string
- format represents the datetime format
- tz specifies local time zone
示例 1:将一个字符串转换为日期时间
在这里,我们将一个字符串作为输入并将其转换为 DateTime。
R
# consider a string
string = "2021-11-21 4:5:23"
# convert string to datetime
final = as.POSIXct(string, format="%Y-%m-%d %H:%M:%S", tz="UTC")
# display
print(final)
# get the type
class(final)
R
# consider a dataframe
dataframe = data.frame(data = c( "2021-11-21 4:5:23",
"2021-11-22 4:5:23",
"2021-11-23 4:5:23",
"2021-11-24 4:5:23",
"2021-11-25 4:5:23"))
# convert data column to datetime
print(as.POSIXct(dataframe$data,
format="%Y-%m-%d %H:%M:%S",
tz="UTC"))
输出:
[1] "2021-11-21 04:05:23 UTC"
[1] "POSIXct" "POSIXt"
示例 2:将字符串列转换为日期时间
在这里,我们从数据框中获取一个字符串,然后转换为 DateTime
Syntax: as.POSIXct(dataframe$column_name, format=”%Y-%m-%d %H:%M:%S”, tz=”UTC”)
where,
- dataframe is the input dataframe
- column_name is the string datetime column
R
# consider a dataframe
dataframe = data.frame(data = c( "2021-11-21 4:5:23",
"2021-11-22 4:5:23",
"2021-11-23 4:5:23",
"2021-11-24 4:5:23",
"2021-11-25 4:5:23"))
# convert data column to datetime
print(as.POSIXct(dataframe$data,
format="%Y-%m-%d %H:%M:%S",
tz="UTC"))
输出:
[1] "2021-11-21 04:05:23 UTC" "2021-11-22 04:05:23 UTC"
[3] "2021-11-23 04:05:23 UTC" "2021-11-24 04:05:23 UTC"
[5] "2021-11-25 04:05:23 UTC"