如何防止write.csv更改POSIXct，日期和时间类返回到字符/因素？ [英] How to prevent write.csv from changing POSIXct, dates and times class back to character/factors?

问题描述

我有一个.csv文件，每个文件有一个字段，用于日期时间，日期和时间。
原来他们都是字符字段，我已经相应地转换了它们。
在代码结尾处，如果我这样做：

  str（data）
 
  datetime ：POSIXct 
日期：日期
时间：类'times'atomic [1：2820392]（....）attr（*，format）= chrh：m：s
  
现在，我很高兴这个，我想创建一个.csv文件，所以这就是我有：
  write.csv（data，file =data.csv，row.names = FALSE）
  
我也尝试过
  write.table（data，data.csv，sep =，，row.names = FALSE）
  
而且，我得到的结果与两者相同，这就是我写的新的.csv的所有转换都会丢失：一切都回到了一个字符。 
 
 
 
我怀疑我在写功能中缺少一些参数，但是我一直在搜索整个下午，我找不到什么。可以请帮忙吗？
解决方案
根据？write.table  
 
 
数据框中列表或具有类（例如
日期）的列将由相应的 as.character'方法：
这样的列默认是不引用的。
 
 
简单的说，你只能写文字/字符到文本文件。如果要保留对象的二进制R表示，请使用 save 。
 
I have a .csv file with one field each for datetime, date and time.
Originally they are all character fields and I have converted them accordingly.
At the end of my code, if I do:
str(data)
I will get
datetime: POSIXct
date: Date
time: Class 'times'  atomic [1:2820392] (....) attr(*, "format")= chr "h:m:s"
Now, I am very happy with this and I want to create a .csv file, so this is what I have:
write.csv(data, file = "data.csv", row.names = FALSE)
I have also tried
write.table(data, "data.csv", sep = ",", row.names = FALSE)
And I get the same result with both, which is all my convertion gets lost when writing the new .csv: everything is back to being a character. 

I suspect I am missing some argument in the write function, but I have been searching all afternoon and I can't find out what. Can some please help?
解决方案
According to ?write.table:

  
Any columns in a data frame which are lists or have a class (e.g.
  dates) will be converted by the appropriate 'as.character' method:
  such columns are unquoted by default.
Simply put, you can only write text/characters to text files. Use save if you want to preserve the binary R representation of your object(s).

                        
这篇关于如何防止write.csv更改POSIXct，日期和时间类返回到字符/因素？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！