R help - Dec 2008 - Help: Some problem with "gdata" package when using Dates

Dear List:
I encountered this strange problem. I want to read dates in a R program.
This is a sample data:
Dates
12/12/08
14/12/08
18/01/08
28/02/08
16/06/08
19/07/08
28/09/08

If I save these dates in a .csv file, and read it in R using
"read.csv", I
can perfectly read the data, and the commands "months(Dates)",
"days(Dates)"
work perfectly fine. On the other hand, if I save this data as an .xls file,
and then read it in R using the "gdata" package using the command
"read.xls("/.../.../Dates.xls",sheet=1,header=T)", and then
attempt to read
the months using months(Dates), this is the output that I
get:
> months(Dates)
[1] Dec Dec Jan Mar Jun Jul Sep
12 Levels: Jan < Feb < Mar < Apr < May < Jun < Jul < Aug
< Sep < ... < Dec
The fourth observation is wrongly read as "Mar" whereas it should be
read as
"Feb". I am not able to make out the error. Am I making a mistake in
reading
the dates from the read.xls command?
Thanks.

-- 
Prabhanjan N. Tattar
Bangalore


-- 
Prabhanjan N. Tattar
Lead Statistician
CustomerXPS
Bangalore

	[[alternative HTML version deleted]]

Convert the date column to Date class and then
access that column, not the entire data frame:
> library(gdata)
> Dates <- read.xls("/tmp2/date.xls", header = FALSE)
Converting xls file to csv file... Done.
Reading csv file... Done.
> months(as.Date(Dates[[1]], "%m-%d-%y"))
[1] "December"  "December"  "January"  
"February"  "June"      "July"
     "September"



On Thu, Dec 18, 2008 at 5:27 AM, Prabhanjan Tattar
<prabhanjannt at gmail.com> wrote:
> Dear List:
> I encountered this strange problem. I want to read dates in a R program.
> This is a sample data:
> Dates
> 12/12/08
> 14/12/08
> 18/01/08
> 28/02/08
> 16/06/08
> 19/07/08
> 28/09/08
>
> If I save these dates in a .csv file, and read it in R using
"read.csv", I
> can perfectly read the data, and the commands "months(Dates)",
"days(Dates)"
> work perfectly fine. On the other hand, if I save this data as an .xls
file,
> and then read it in R using the "gdata" package using the command
> "read.xls("/.../.../Dates.xls",sheet=1,header=T)", and
then attempt to read
> the months using months(Dates), this is the output that I get:
>> months(Dates)
> [1] Dec Dec Jan Mar Jun Jul Sep
> 12 Levels: Jan < Feb < Mar < Apr < May < Jun < Jul <
Aug < Sep < ... < Dec
> The fourth observation is wrongly read as "Mar" whereas it should
be read as
> "Feb". I am not able to make out the error. Am I making a mistake
in reading
> the dates from the read.xls command?
> Thanks.
>
> --
> Prabhanjan N. Tattar
> Bangalore
>
>
> --
> Prabhanjan N. Tattar
> Lead Statistician
> CustomerXPS
> Bangalore
>
>        [[alternative HTML version deleted]]
>
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