[R] fridays date to date

[Greg Snow]

If you know that your first date is a Friday then you can use seq with
by="7 day", then you don't need to post filter the vector.

On Thu, Mar 1, 2012 at 1:40 PM, Ben quant <ccquant at gmail.com> wrote:
> Great thanks!
>
> ben
>
> On Thu, Mar 1, 2012 at 1:30 PM, Marc Schwartz <marc_schwartz at me.com> wrote:
>
>> On Mar 1, 2012, at 2:02 PM, Ben quant wrote:
>>
>> > Hello,
>> >
>> > How do I get the dates of all Fridays between two dates?
>> >
>> > thanks,
>> >
>> > Ben
>>
>>
>> Days <- seq(from = as.Date("2012-03-01"),
>>            to = as.Date("2012-07-31"),
>>            by = "day")
>>
>> > str(Days)
>>  Date[1:153], format: "2012-03-01" "2012-03-02" "2012-03-03" "2012-03-04"
>> ...
>>
>> # See ?weekdays
>>
>> > Days[weekdays(Days) == "Friday"]
>>  [1] "2012-03-02" "2012-03-09" "2012-03-16" "2012-03-23" "2012-03-30"
>>  [6] "2012-04-06" "2012-04-13" "2012-04-20" "2012-04-27" "2012-05-04"
>> [11] "2012-05-11" "2012-05-18" "2012-05-25" "2012-06-01" "2012-06-08"
>> [16] "2012-06-15" "2012-06-22" "2012-06-29" "2012-07-06" "2012-07-13"
>> [21] "2012-07-20" "2012-07-27"
>>
>> HTH,
>>
>> Marc Schwartz
>>
>>
>
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>
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-- 
Gregory (Greg) L. Snow Ph.D.
538280 at gmail.com