I tried downloading using as.is and have also provided the dput below. The
date for example is 20/4/2012 and wday gives 2 instead of 6? Thanks for all
your help.

> str(test1)
'data.frame':   1825 obs. of  7 variables:
 $ Date     : chr  "20/04/2012" "19/04/2012" "18/04/2012" "17/04/2012" ...
 $ Open     : num  2.33 2.35 2.35 2.34 2.32 2.34 2.3 2.28 2.29 2.28 ...
 $ High     : num  2.34 2.36 2.38 2.34 2.35 2.36 2.32 2.29 2.33 2.3 ...
 $ Low      : num  2.31 2.33 2.34 2.3 2.31 2.32 2.29 2.25 2.28 2.28 ...
 $ Close    : num  2.31 2.35 2.36 2.33 2.31 2.32 2.31 2.26 2.3 2.29 ...
 $ Volume   : int  5366000 5382000 9606000 9596000 5941000 10332000 7000000
9636000 6019000 3279000 ...
 $ Adj.Close: num  2.31 2.35 2.36 2.33 2.31 2.32 2.31 2.26 2.3 2.29 ...
> wday(test$Date[1])
[1] 2
> wday(test1$Date[1])
[1] 2
> test1%Date[1]
Error: unexpected input in "test1%Date[1]"
> test1$Date[1]
[1] "20/04/2012"
>
> dput(test1)
structure(list(Date = c("20/04/2012", "19/04/2012", "18/04/2012",
"17/04/2012", "16/04/2012", "13/04/2012", "12/04/2012", "11/04/2012",
"10/04/2012", "09/04/2012", "05/04/2012", "04/04/2012", "03/04/2012",
"02/04/2012", "30/03/2012", "29/03/2012", "28/03/2012", "27/03/2012",
"26/03/2012", "23/03/2012", "21/03/2012", "20/03/2012", "19/03/2012",
"16/03/2012", "15/03/2012", "14/03/2012", "13/03/2012", "12/03/2012",
"09/03/2012", "08/03/2012", "07/03/2012", "06/03/2012", "05/03/2012",
"02/03/2012", "01/03/2012", "29/02/2012", "28/02/2012", "27/02/2012",
"24/02/2012", "23/02/2012", "22/02/2012", "21/02/2012", "20/02/2012",
"17/02/2012", "16/02/2012", "15/02/2012", "14/02/2012", "13/02/2012",
"10/02/2012", "09/02/2012", "08/02/2012", "07/02/2012", "06/02/2012",
"03/02/2012", "02/02/2012", "01/02/2012", "31/01/2012", "30/01/2012",
"27/01/2012", "26/01/2012", "25/01/2012", "20/01/2012", "19/01/2012",
"18/01/2012", "17/01/2012", "16/01/2012", "13/01/2012", "12/01/2012",
"11/01/2012", "10/01/2012", "09/01/2012", "06/01/2012", "05/01/2012",
"04/01/2012", "03/01/2012", "30/12/2011", "29/12/2011", "28/12/2011",
"27/12/2011", "23/12/2011", "22/12/2011", "21/12/2011", "20/12/2011",
"19/12/2011", "16/12/2011", "15/12/2011", "14/12/2011", "13/12/2011",
"12/12/2011", "09/12/2011", "08/12/2011", "07/12/2011", "06/12/2011",
"05/12/2011", "02/12/2011", "01/12/2011", "30/11/2011", "29/11/2011",
"28/11/2011", "25/11/2011", "24/11/2011", "23/11/2011", "22/11/2011",
"21/11/2011", "18/11/2011", "17/11/2011", "16/11/2011", "15/11/2011",
"14/11/2011", "11/11/2011", "10/11/2011", "09/11/2011", "08/11/2011",
"04/11/2011", "03/11/2011", "02/11/2011", "01/11/2011", "31/10/2011",
"28/10/2011", "27/10/2011", "25/10/2011", "24/10/2011", "21/10/2011",
"20/10/2011", "19/10/2011", "18/10/2011", "17/10/2011", "14/10/2011",
"13/10/2011", "12/10/2011", "11/10/2011", "10/10/2011", "07/10/2011",
"06/10/2011", "05/10/2011", "04/10/2011", "03/10/2011", "30/09/2011",
"29/09/2011", "28/09/2011", "27/09/2011", "26/09/2011", "23/09/2011",
"22/09/2011", "21/09/2011", "20/09/2011", "19/09/2011", "16/09/2011",
"15/09/2011", "14/09/2011", "13/09/2011", "12/09/2011", "09/09/2011",
"08/09/2011", "07/09/2011", "06/09/2011", "05/09/2011", "02/09/2011",
"01/09/2011", "31/08/2011", "29/08/2011", "26/08/2011", "25/08/2011",
"24/08/2011", "23/08/2011", "22/08/2011", "19/08/2011", "18/08/2011",
"17/08/2011", "16/08/2011", "15/08/2011", "12/08/2011", "11/08/2011",
"10/08/2011", "08/08/2011", "05/08/2011", "04/08/2011", "03/08/2011",
"02/08/2011", "01/08/2011", "29/07/2011", "28/07/2011", "27/07/2011",
"26/07/2011", "25/07/2011", "22/07/2011", "21/07/2011", "20/07/2011",
"19/07/2011", "18/07/2011", "15/07/2011", "14/07/2011", "13/07/2011",
"12/07/2011", "11/07/2011", "08/07/2011", "07/07/2011", "06/07/2011",
"05/07/2011", "04/07/2011", "01/07/2011", "30/06/2011", "29/06/2011",
"28/06/2011", "27/06/2011", "24/06/2011", "23/06/2011", "22/06/2011",
"21/06/2011", "20/06/2011", "17/06/2011", "16/06/2011", "15/06/2011",
"14/06/2011", "13/06/2011", "10/06/2011", "09/06/2011", "08/06/2011",
"07/06/2011", "06/06/2011", "03/06/2011", "02/06/2011", "01/06/2011",
"31/05/2011", "30/05/2011", "27/05/2011", "26/05/2011", "25/05/2011",
"24/05/2011", "23/05/2011", "20/05/2011", "19/05/2011", "18/05/2011",
"16/05/2011", "13/05/2011", "12/05/2011", "11/05/2011", "10/05/2011",
"09/05/2011", "06/05/2011", "05/05/2011", "04/05/2011", "03/05/2011",
"29/04/2011", "28/04/2011", "27/04/2011", "26/04/2011", "25/04/2011",
"21/04/2011", "20/04/2011", "19/04/2011", "18/04/2011", "15/04/2011",
"14/04/2011", "13/04/2011", "12/04/2011", "11/04/2011", "08/04/2011",
"07/04/2011", "06/04/2011", "05/04/2011", "04/04/2011", "01/04/2011",
"31/03/2011", "30/03/2011", "29/03/2011", "28/03/2011", "25/03/2011",
"24/03/2011", "23/03/2011", "22/03/2011", "21/03/2011", "18/03/2011",
"17/03/2011", "16/03/2011", "15/03/2011", "14/03/2011", "11/03/2011",
"10/03/2011", "09/03/2011", "08/03/2011", "07/03/2011", "04/03/2011",
"03/03/2011", "02/03/2011", "01/03/2011", "28/02/2011", "25/02/2011",
"24/02/2011", "23/02/2011", "22/02/2011", "21/02/2011", "18/02/2011",
"17/02/2011", "16/02/2011", "15/02/2011", "14/02/2011", "11/02/2011",
"10/02/2011", "09/02/2011", "08/02/2011", "07/02/2011", "02/02/2011",
"01/02/2011", "31/01/2011", "28/01/2011", "27/01/2011", "26/01/2011",
"25/01/2011", "24/01/2011", "21/01/2011", "20/01/2011", "19/01/2011",
"18/01/2011", "17/01/2011", "14/01/2011", "13/01/2011", "12/01/2011",
"11/01/2011", "10/01/2011", "07/01/2011", "06/01/2011", "05/01/2011",
"04/01/2011", "03/01/2011", "31/12/2010", "30/12/2010", "29/12/2010",
"28/12/2010", "27/12/2010", "24/12/2010", "23/12/2010", "22/12/2010",
"21/12/2010", "20/12/2010", "17/12/2010", "16/12/2010", "15/12/2010",
"14/12/2010", "13/12/2010", "10/12/2010", "09/12/2010", "08/12/2010",
"07/12/2010", "06/12/2010", "03/12/2010", "02/12/2010", "01/12/2010",
"30/11/2010", "29/11/2010", "26/11/2010", "25/11/2010", "24/11/2010",
"23/11/2010", "22/11/2010", "19/11/2010", "18/11/2010", "16/11/2010",
"15/11/2010", "12/11/2010", "11/11/2010", "10/11/2010", "09/11/2010",
"08/11/2010", "04/11/2010", "03/11/2010", "02/11/2010", "01/11/2010",
"29/10/2010", "28/10/2010", "27/10/2010", "26/10/2010", "25/10/2010",
"22/10/2010", "21/10/2010", "20/10/2010", "19/10/2010", "18/10/2010",
"15/10/2010", "14/10/2010", "13/10/2010", "12/10/2010", "11/10/2010",
"08/10/2010", "07/10/2010", "06/10/2010", "05/10/2010", "04/10/2010",
"01/10/2010", "30/09/2010", "29/09/2010", "28/09/2010", "27/09/2010",
"24/09/2010", "23/09/2010", "22/09/2010", "21/09/2010", "20/09/2010",
"17/09/2010", "16/09/2010", "15/09/2010", "14/09/2010", "13/09/2010",
"09/09/2010", "08/09/2010", "07/09/2010", "06/09/2010", "03/09/2010",
"02/09/2010", "01/09/2010", "31/08/2010", "30/08/2010", "27/08/2010",
"26/08/2010", "25/08/2010", "24/08/2010", "23/08/2010", "20/08/2010",
"19/08/2010", "18/08/2010", "17/08/2010", "16/08/2010", "13/08/2010",
"12/08/2010", "11/08/2010", "10/08/2010", "06/08/2010", "05/08/2010",
"04/08/2010", "03/08/2010", "02/08/2010", "30/07/2010", "29/07/2010",
"28/07/2010", "27/07/2010", "26/07/2010", "23/07/2010", "22/07/2010",
"21/07/2010", "20/07/2010", "19/07/2010", "16/07/2010", "15/07/2010",
"14/07/2010", "13/07/2010", "12/07/2010", "09/07/2010", "08/07/2010",
"07/07/2010", "06/07/2010", "05/07/2010", "02/07/2010", "01/07/2010",
"30/06/2010", "29/06/2010", "28/06/2010", "25/06/2010", "24/06/2010",
"23/06/2010", "22/06/2010", "21/06/2010", "18/06/2010", "17/06/2010",
"16/06/2010", "15/06/2010", "14/06/2010", "11/06/2010", "10/06/2010",
"09/06/2010", "08/06/2010", "07/06/2010", "04/06/2010", "03/06/2010",
"02/06/2010", "01/06/2010", "31/05/2010", "27/05/2010", "26/05/2010",
"25/05/2010", "24/05/2010", "21/05/2010", "20/05/2010", "19/05/2010",
"18/05/2010", "17/05/2010", "14/05/2010", "13/05/2010", "12/05/2010",
"11/05/2010", "10/05/2010", "07/05/2010", "06/05/2010", "05/05/2010",
"04/05/2010", "03/05/2010", "30/04/2010", "29/04/2010", "28/04/2010",
"27/04/2010", "26/04/2010", "23/04/2010", "22/04/2010", "21/04/2010",
"20/04/2010", "19/04/2010", "16/04/2010", "15/04/2010", "14/04/2010",
"13/04/2010", "12/04/2010", "09/04/2010", "08/04/2010", "07/04/2010",
"06/04/2010", "05/04/2010", "01/04/2010", "31/03/2010", "30/03/2010",
"29/03/2010", "26/03/2010", "25/03/2010", "24/03/2010", "23/03/2010",
"22/03/2010", "19/03/2010", "18/03/2010", "17/03/2010", "16/03/2010",
"15/03/2010", "12/03/2010", "11/03/2010", "10/03/2010", "09/03/2010",
"08/03/2010", "05/03/2010", "04/03/2010", "03/03/2010", "02/03/2010",
"01/03/2010", "26/02/2010", "25/02/2010", "24/02/2010", "23/02/2010",
"22/02/2010", "19/02/2010", "18/02/2010", "17/02/2010", "12/02/2010",
"11/02/2010", "10/02/2010", "09/02/2010", "08/02/2010", "05/02/2010",
"04/02/2010", "03/02/2010", "02/02/2010", "01/02/2010", "29/01/2010",
"28/01/2010", "27/01/2010", "26/01/2010", "25/01/2010", "22/01/2010",
"21/01/2010", "20/01/2010", "19/01/2010", "18/01/2010", "15/01/2010",
"14/01/2010", "13/01/2010", "12/01/2010", "11/01/2010", "08/01/2010",
"07/01/2010", "06/01/2010", "05/01/2010", "04/01/2010", "31/12/2009",
"30/12/2009", "29/12/2009", "28/12/2009", "24/12/2009", "23/12/2009",
"22/12/2009", "21/12/2009", "18/12/2009", "17/12/2009", "16/12/2009",
"15/12/2009", "14/12/2009", "11/12/2009", "10/12/2009", "09/12/2009",
"08/12/2009", "07/12/2009", "04/12/2009", "03/12/2009", "02/12/2009",
"01/12/2009", "30/11/2009", "26/11/2009", "25/11/2009", "24/11/2009",
"23/11/2009", "20/11/2009", "19/11/2009", "18/11/2009", "17/11/2009",
"16/11/2009", "13/11/2009", "12/11/2009", "11/11/2009", "10/11/2009",
"09/11/2009", "06/11/2009", "05/11/2009", "04/11/2009", "03/11/2009",
"02/11/2009", "30/10/2009", "29/10/2009", "28/10/2009", "27/10/2009",
"26/10/2009", "23/10/2009", "22/10/2009", "21/10/2009", "20/10/2009",
"19/10/2009", "16/10/2009", "15/10/2009", "14/10/2009", "13/10/2009",
"12/10/2009", "09/10/2009", "08/10/2009", "07/10/2009", "06/10/2009",
"05/10/2009", "02/10/2009", "01/10/2009", "30/09/2009", "29/09/2009",
"28/09/2009", "25/09/2009", "24/09/2009", "23/09/2009", "22/09/2009",
"18/09/2009", "17/09/2009", "16/09/2009", "15/09/2009", "14/09/2009",
"11/09/2009", "10/09/2009", "09/09/2009", "08/09/2009", "07/09/2009",
"04/09/2009", "03/09/2009", "02/09/2009", "01/09/2009", "31/08/2009",
"28/08/2009", "27/08/2009", "26/08/2009", "25/08/2009", "24/08/2009",
"21/08/2009", "20/08/2009", "19/08/2009", "18/08/2009", "17/08/2009",
"14/08/2009", "13/08/2009", "12/08/2009", "11/08/2009", "07/08/2009",
"06/08/2009", "05/08/2009", "04/08/2009", "03/08/2009", "31/07/2009",
"30/07/2009", "29/07/2009", "28/07/2009", "27/07/2009", "24/07/2009",
"23/07/2009", "22/07/2009", "21/07/2009", "20/07/2009", "17/07/2009",
"16/07/2009", "15/07/2009", "14/07/2009", "13/07/2009", "10/07/2009",
"09/07/2009", "08/07/2009", "07/07/2009", "06/07/2009", "03/07/2009",
"02/07/2009", "01/07/2009", "30/06/2009", "29/06/2009", "26/06/2009",
"25/06/2009", "24/06/2009", "23/06/2009", "22/06/2009", "19/06/2009",
"18/06/2009", "17/06/2009", "16/06/2009", "15/06/2009", "12/06/2009",
"11/06/2009", "10/06/2009", "09/06/2009", "08/06/2009", "05/06/2009",
"04/06/2009", "03/06/2009", "02/06/2009", "01/06/2009", "29/05/2009",
"28/05/2009", "27/05/2009", "26/05/2009", "25/05/2009", "22/05/2009",
"21/05/2009", "20/05/2009", "19/05/2009", "18/05/2009", "15/05/2009",
"14/05/2009", "13/05/2009", "12/05/2009", "11/05/2009", "08/05/2009",
"07/05/2009", "06/05/2009", "05/05/2009", "04/05/2009", "30/04/2009",
"29/04/2009", "28/04/2009", "27/04/2009", "24/04/2009", "23/04/2009",
"22/04/2009", "21/04/2009", "20/04/2009", "17/04/2009", "16/04/2009",
"15/04/2009", "14/04/2009", "13/04/2009", "09/04/2009", "08/04/2009",





On Sun, Apr 22, 2012 at 6:41 PM, Jeff Newmiller <jdnewmil@dcn.davis.ca.us>wrote:

> On Sun, 22 Apr 2012, Hasan Diwan wrote:
>
> Raghu,
>>
>> On 22 April 2012 09:53, Raghuraman Ramachandran <optionsraghu@gmail.com
>> >wrote:
>>
>> I have a data frame (from CSV file) which has its first column called
>>> Date.
>>> The Date is in the format mm/dd/yyyy. I was trying to get the weekday for
>>> these dates and I tried using wday() and day.of.week() functions and both
>>> of them gave me precisely the wrong answers. I think the issue lies in
>>> the
>>> proper formatting of dates. The class of this column is a factor class
>>> and
>>> hence I tried converting into POSIXlt, xts, zoo objects and yet I could
>>> not
>>> get the weekday correctly. Anyone has any suggestions please?
>>>
>>>
>> Try this:
>> # assume dataIn is where the CSV files data is...
>> dataIn$Date <- as.POSIXct(dataIn$Date, format='%m/%d/%y')
>>
>
> By far the most common error I see is failing to import the Date column as
> character, instead allowing the import function to convert it to factor,
> after which computations (such as the above suggestion) use the hidden
> factor index instead of the visible character representation, which further
> mystifies beginners.  The conversion above will only work correctly if the
> column was imported as character.  E.g.
>
> dataIn <- read.csv( file="yourdatafile", as.is=TRUE )
>
> OP: Use the str() function to see what types you are working with, and in
> future R-help queries send dput() of the data and code you have tried if we
> are to be able to reproduce your attempts effectively rather than reading
> your mind.
>
>
> dataIn <- cbind(dataIn, day.of.week = format(dataIn$Date, format='%A')
>>
>
> Why not just
>
> dataIn$day.of.week <- weekdays( dataIn$Date )
>
> ?
>
> ------------------------------**------------------------------**
> ---------------
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