factor conversion to date/time

[mpostje]

Hi, I've been trying to convert numbers from an online temperature database
into dates and time that R recognizes. I've tried as.Date, as.POSIXlt and strptime  the problem is that the database has put a T between the numbers and R will not accept any conversions. currently it sees the date as a factor with the format  as 1981-01-02T08:00I would like to keep only the year and month, but my primary focus is to get R to recognize it as a date.

Thank you for your help. cheers,Marjolein          
        [[alternative HTML version deleted]]

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[Michael Weylandt]

Please don't triple post.

Michael

On Wed, May 2, 2012 at 8:08 AM, marjolein post <[hidden email]> wrote:

>
>
>
>
> Hi, I've been trying to convert numbers from an online temperature database
> into dates and time that R recognizes. I've tried as.Date, as.POSIXlt and strptime  the problem is that the database has put a T between the numbers and R will not accept any conversions. currently it sees the date as a factor with the format  as 1981-01-02T08:00I would like to keep only the year and month, but my primary focus is to get R to recognize it as a date.
>
> Thank you for your help. cheers,Marjolein
>        [[alternative HTML version deleted]]
>
> ______________________________________________
> [hidden email] mailing list
> 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.

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[Duncan Murdoch-2]

On 02/05/2012 8:08 AM, marjolein post wrote:
>
>
>
> Hi, I've been trying to convert numbers from an online temperature database
> into dates and time that R recognizes. I've tried as.Date, as.POSIXlt and strptime  the problem is that the database has put a T between the numbers and R will not accept any conversions. currently it sees the date as a factor with the format  as 1981-01-02T08:00I would like to keep only the year and month, but my primary focus is to get R to recognize it as a date.

To stop the conversion to factors, use argument stringsAsFactors=FALSE
when you read the file, or even better, options(stringsAsFactors=FALSE)
for a global change.

To convert a string, specify the format (following the instructions in
?strptime):

x <- "1981-01-02T08:00I"
strptime(x, format="%Y-%m-%dT%H:%MI")

Duncan Murdoch

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[John Kane]

Try something like this.  Convert the vector to character and grab the first 10 characters then convert to a date.

aa <- as.factor("1981-01-02T08:00I")
aa <- as.character(aa)
aa <- substr(aa, 1, 10)
class(b)

John Kane
Kingston ON Canada

> -----Original Message-----
> From: [hidden email]
> Sent: Wed, 2 May 2012 14:08:26 +0200
> To: [hidden email]
> Subject: [R] factor conversion to date/time
>
> Hi, I've been trying to convert numbers from an online temperature
> database
> into dates and time that R recognizes. I've tried as.Date, as.POSIXlt and
> strptime  the problem is that the database has put a T between the
> numbers and R will not accept any conversions. currently it sees the date
> as a factor with the format  as 1981-01-02T08:00I would like to keep only
> the year and month, but my primary focus is to get R to recognize it as a
> date.
>
> Thank you for your help. cheers,Marjolein
> [[alternative HTML version deleted]]
>

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