[R] about data format in R

[David Winsemius]

> On Dec 31, 2016, at 9:26 AM, lily li <chocold12 at gmail.com> wrote:
> 
> Hi all,
> 
> Thanks for your help. Now I can convert data to the format "yyyy-mm-dd
> hh:mm:ss", but how to convert it to "yyyy-mm-dd"? The datasets are txt
> files, not from excel.

Use: as.Date
> 
> On Fri, Dec 30, 2016 at 3:01 PM, Duncan Mackay <dulcalma at bigpond.com> wrote:
> 
>> Hi
>> 
>> Is this the output from Excel?
>> If so format it in Excel for a date format not a date-time format .
>> Depending how the dates were inputted into Excel and the Excel setup a date
>> may not be a date format.
>> There are no rules with microsoft formatting so beware!
>> 
>> 
>> Regards
>> 
>> Duncan
>> 
>> Duncan Mackay
>> Department of Agronomy and Soil Science
>> University of New England
>> Armidale NSW 2351
>> Email: home: mackay at northnet.com.au
>> 
>> -----Original Message-----
>> From: R-help [mailto:r-help-bounces at r-project.org] On Behalf Of lily li
>> Sent: Saturday, 31 December 2016 05:38
>> To: Rui Barradas
>> Cc: R mailing list
>> Subject: Re: [R] about data format in R
>> 
>> Hi Rui,
>> 
>> Thanks for your reply. When I read in data using my code, the first column
>> ranges from 0 to 1. So when I use the code you wrote, it shows the error
>> message:
>> Error in as.POSIXct.numeric(DF$Date, format = "%m/%d/%Y-%H:%M:%S") :
>> 'origin' must be supplied
>> 
>> 
>> On Fri, Dec 30, 2016 at 11:23 AM, Rui Barradas <ruipbarradas at sapo.pt>
>> wrote:
>> 
>>> Hello,
>>> 
>>> Have you tried
>>> 
>>> df$date <- as.POSIXct(dat$date, format = "%m/%d/%Y-%H:%M:%S")
>>> 
>>> ?
>>> 
>>> Hope this helps,
>>> 
>>> Rui Barradas
>>> 
>>> 
>>> 
>>> Em 30-12-2016 17:40, lily li escreveu:
>>> 
>>>> Hi R users,
>>>> 
>>>> I'm trying to read in data, and then plot time series data. However, I
>>>> have
>>>> some problems. In my dataset, the first column represents time, and in
>> the
>>>> format:
>>>> mm/dd/yyyy-hr:min:sec; For example, 10/01/1995-00:00:00,
>>>> 10/01/1995-06:00:00, etc.
>>>> 
>>>> df:
>>>>            date                    evap     precip    intercept
>>>> 10/01/1995-00:00:00       1.5          2            0.2
>>>> 10/01/1995-12:00:00       1.7          2.2         0.1
>>>> 10/02/1995-00:00:00       1.5          1.8         0.3
>>>> ...
>>>> 
>>>> My code is like this
>>>> file1 = read.table('df', head=T)
>>>> 
>>>> When I read in data, I found that it read incorrectly. How to format
>> when
>>>> read in data? Thanks.
>>>> 
>>>>        [[alternative HTML version deleted]]
>>>> 
>>>> ______________________________________________
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>>>> ng-guide.html
>>>> and provide commented, minimal, self-contained, reproducible code.
>>>> 
>>>> 
>> 
>>        [[alternative HTML version deleted]]
>> 
>> ______________________________________________
>> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide http://www.R-project.org/
>> posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>> 
>> ______________________________________________
>> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide http://www.R-project.org/
>> posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>> 
> 
> 	[[alternative HTML version deleted]]
> 
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.

David Winsemius
Alameda, CA, USA