R help - Apr 2009 - Problem with Dates :-(

Dear R users, 
I know, the question is bit old one. :-(

Ok. I have a table with say three columns and 70 rows.
The second column has dates in format dd.mm.yy (i.e. 01.10.07 indicating
record for October 1, 2007).
I read the text file, containing the records. Now, I want to find out the
weekday for each date.
However, I cannot do so.

1)
If I type result[1,"Date"] to see the Date in the first row, I get
following
output:
70 Levels: 01.10.07 01.11.07 02.10.07 02.12.07.. and so on.

2)
If I use any functions related to Date or time, I get the message: character
string is not in a standard unambigious format.
:-(

I can understand that first I have to "convert" the existing date
format to
such a format that R "recognizes" as date format. However, I am not
able to
do so.

I did try to use format.Date() and as.Date() functions. However, no success. 
I am making some silly mistake. 
Please help.


Thank you.

Best Regards,
Suresh



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Suresh_FSFM wrote:
> Dear R users, 
> I know, the question is bit old one. :-(
> 
> Ok. I have a table with say three columns and 70 rows.
> The second column has dates in format dd.mm.yy (i.e. 01.10.07 indicating
> record for October 1, 2007).
> I read the text file, containing the records. Now, I want to find out the
> weekday for each date.
> However, I cannot do so.
> 
> 1)
> If I type result[1,"Date"] to see the Date in the first row, I
get following
> output:
> 70 Levels: 01.10.07 01.11.07 02.10.07 02.12.07.. and so on.
> 
> 2)
> If I use any functions related to Date or time, I get the message:
character
> string is not in a standard unambigious format.
> :-(
> 
> I can understand that first I have to "convert" the existing date
format to
> such a format that R "recognizes" as date format. However, I am
not able to
> do so.
> 
> I did try to use format.Date() and as.Date() functions. However, no
success.
> I am making some silly mistake. 
> Please help.

If you want Date rather than some posic format, use

newDate <- as.Date(result[,"Date"], "%d.%m.%y"))

Uew Ligges



> 
> Thank you.
> 
> Best Regards,
> Suresh
> 
> 
>