[R] Sorting a date vector

RON70 ron_michael70 at yahoo.com
Tue Dec 16 14:24:45 CET 2008


Yes you are right. However using that code, format of date is altered. I need
to main same format as the input data i.e. "10-02-2008" not "2008-10-02",
still having date-class. Any better idea?


David Winsemius wrote:
> 
> You might want to look at your date format more closely. Both the  
> separator and the year format specs fail to match your input.
> 
>  > as.Date("10-02-2008", format = "%m/%d/%y")
> [1] NA
>  > as.Date("10-02-2008", format = "%m-%d-%Y")
> [1] "2008-10-02"
> 
> -- 
> David Winsemius
> On Dec 16, 2008, at 7:54 AM, RON70 wrote:
> 
>>
>> I have a date-like-vector like :
>>
>>> date_file
>> "10-02-2008" "10-03-2008" "10-06-2008" "10-07-2008" "10-09-2008"
>> "10-10-2008" "10-13-2008" "10-14-2008" "10-15-2008"
>> "10-16-2008" "10-17-2008" "10-20-2008" "10-21-2008" "10-22-2008"
>> "10-23-2008" "10-24-2008" "10-28-2008" "10-29-2008"
>> "10-30-2008" "10-31-2008" "11-03-2008" "11-04-2008" "11-05-2008"
>> "11-06-2008" "11-07-2008" "11-10-2008" "11-11-2008"
>> "11-12-2008" "11-13-2008" "11-14-2008" "11-17-2008" "11-18-2008"
>> "11-19-2008" "11-20-2008" "11-21-2008" "11-24-2008"
>> "11-25-2008" "11-26-2008" "11-28-2008" "12-01-2008" "12-02-2008"
>> "12-03-2008" "12-04-2008" "12-05-2008" "12-08-2008"
>> "12-09-2008" "12-10-2008" "12-11-2008" "12-12-2008" "12-15-2008"
>> "4-18-2008"  "4-21-2008"  "4-22-2008"  "4-23-2008"
>> "4-24-2008"  "4-28-2008"  "4-29-2008"  "5-01-2008"  "5-05-2008"
>> "5-06-2008"  "5-07-2008"  "5-09-2008"  "5-12-2008"
>> "5-13-2008"  "5-14-2008"  "5-15-2008"  "5-16-2008"  "5-19-2008"
>> "5-20-2008"  "5-21-2008"  "5-22-2008"  "5-23-2008"
>> "5-27-2008"  "5-28-2008"  "5-29-2008"  "5-30-2008"  "6-02-2008"
>> "6-03-2008"  "6-05-2008"  "6-06-2008"  "6-09-2008"
>> "6-10-2008"  "6-11-2008"  "6-12-2008"  "6-13-2008"  "6-17-2008"
>> "6-18-2008"  "6-19-2008"  "6-20-2008"  "6-23-2008"
>> "6-24-2008"  "6-25-2008"  "6-26-2008"  "6-27-2008"  "7-01-2008"
>> "7-02-2008"  "7-04-2008"  "7-07-2008"  "7-08-2008"
>> "7-09-2008"  "7-10-2008"  "7-11-2008"  "7-15-2008"  "7-16-2008"
>> "7-18-2008"  "7-21-2008"  "7-22-2008"  "7-23-2008"
>> "7-24-2008"  "7-25-2008"  "7-28-2008"  "7-30-2008"  "7-31-2008"
>> "8-01-2008"  "8-04-2008"  "8-05-2008"  "8-06-2008"
>> "8-07-2008"  "8-08-2008"  "8-11-2008"  "8-12-2008"  "8-13-2008"
>> "8-15-2008"  "8-18-2008"  "8-19-2008"  "8-20-2008"
>> "8-21-2008"  "8-22-2008"  "8-25-2008"  "8-26-2008"  "8-27-2008"
>> "8-28-2008"  "8-29-2008"  "9-03-2008"  "9-04-2008"
>> "9-05-2008"  "9-08-2008"  "9-09-2008"  "9-10-2008"  "9-11-2008"
>> "9-12-2008"  "9-15-2008"  "9-16-2008"  "9-17-2008"
>> "9-18-2008"  "9-19-2008"  "9-22-2008"  "9-23-2008"  "9-24-2008"
>> "9-25-2008"  "9-26-2008"  "9-29-2008"  "9-30-2008"
>>
>> I wanted to sort this in ascending order. I tried using simply sort()
>> function, without altering the format of date, but it didnot work.  
>> Next I
>> tried to convert that vector in a date-class vector so that, I could  
>> sort
>> them but in vein :(
>>
>> I used :
>> as.Date(date_file, format="%m/%d/%y")
>>
>> However it did not work.
>>
>> Can anyone please tell me what would be correct approach?
>> -- 
>> View this message in context:
>> http://www.nabble.com/Sorting-a-date-vector-tp21032540p21032540.html
>> Sent from the R help mailing list archive at Nabble.com.
>>
>> ______________________________________________
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>> PLEASE do read the posting guide
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>> and provide commented, minimal, self-contained, reproducible code.
> 
> ______________________________________________
> R-help at r-project.org 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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