Re: [R] Finding a date 6 months before
Dear Gabor,
Fantastic! Thank you very much for your help, as always!
Regards,
Sergey
On Wed, Mar 3, 2010 at 12:24, Gabor Grothendieck
wrote:
> Try this. as.Date(as.yearmon(today) - 6/12) gives the 1st of the
> month 6 months ago and the remainder of that line moves ahead by d-1
> days if its the d-th day of the month now.
>
>> library(zoo)
>> z <- zoo(0:399, as.Date("2009-06-01")+0:399)
>> today <- Sys.Date(); today
> [1] "2010-03-03"
>> ago6mos <- as.Date(as.yearmon(today) - 6/12) - 1 + as.numeric(format(today,
>> "%d"))
>> window(z, index = ago6mos)
> 2009-09-03
> 94
>
> If we are at the last day of the month and 6 months ago that month has
> fewer days than today's month then what to do is not well defined but
> we resolve that here by just moving ahead d-1 days anyways.
>
> On Wed, Mar 3, 2010 at 6:07 AM, Sergey Goriatchev wrote:
>> Hello everyone
>>
>> I use zoo objects and I need to find a date 6 months before today's date.
>>
>> Example, today we have 3rd March 2010, I need to find the date 3rd
>> September 2009.
>>
>> How could I do that, please?
>>
>>
>> Regards,
>> Sergey
>>
>> --
>> Simplicity is the last step of art./Bruce Lee
>> The more you know, the more you know you don't know.
>>
>> __
>> R-help@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.
>>
>
--
Simplicity is the last step of art./Bruce Lee
The more you know, the more you know you don't know. /Myself
I'm not young enough to know everything. /Oscar Wilde
Experience is one thing you can't get for nothing. /Oscar Wilde
When you are finished changing, you're finished. /Benjamin Franklin
Luck is where preparation meets opportunity. /George Patten
Kniven skärpes bara mot stenen.
__
R-help@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.
Re: [R] Finding a date 6 months before
Try this. as.Date(as.yearmon(today) - 6/12) gives the 1st of the
month 6 months ago and the remainder of that line moves ahead by d-1
days if its the d-th day of the month now.
> library(zoo)
> z <- zoo(0:399, as.Date("2009-06-01")+0:399)
> today <- Sys.Date(); today
[1] "2010-03-03"
> ago6mos <- as.Date(as.yearmon(today) - 6/12) - 1 + as.numeric(format(today,
> "%d"))
> window(z, index = ago6mos)
2009-09-03
94
If we are at the last day of the month and 6 months ago that month has
fewer days than today's month then what to do is not well defined but
we resolve that here by just moving ahead d-1 days anyways.
On Wed, Mar 3, 2010 at 6:07 AM, Sergey Goriatchev wrote:
> Hello everyone
>
> I use zoo objects and I need to find a date 6 months before today's date.
>
> Example, today we have 3rd March 2010, I need to find the date 3rd
> September 2009.
>
> How could I do that, please?
>
>
> Regards,
> Sergey
>
> --
> Simplicity is the last step of art./Bruce Lee
> The more you know, the more you know you don't know.
>
> __
> R-help@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.
>
__
R-help@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.
[R] Finding a date 6 months before
Hello everyone I use zoo objects and I need to find a date 6 months before today's date. Example, today we have 3rd March 2010, I need to find the date 3rd September 2009. How could I do that, please? Regards, Sergey -- Simplicity is the last step of art./Bruce Lee The more you know, the more you know you don't know. __ R-help@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.
