[R] generate irregular series of dates

[Simon Kiss]

Dear Gabor,
Yours worked really well. For what it's worth, here is the final  
product.
I also added a line or two to reconvert the dates back to written form  
(October 15 2010).


require(chron)
dd <- seq(as.Date("INSERT FIRST DATE OF CLASSES IN TERM HERE"),  
as.Date("INSERT LAST DAY OF CLASSES IN TERM HERE"), "day")
a=as.character(dd[weekdays(dd) %in% c("INSERT FIRST WEEKDAY OF CLASS",  
"INSERT SECOND WEEKDAY OF CLASS")])
a=chron(a, format = c(dates="y-m-d"), out.format=c(dates="month day,  
year"))
write.table(a, "INSERT FILE LOCATION WHERE YOU WISH TO SAVE DATES",  
quote=FALSE, col.names=FALSE, row.names=FALSE)

Thanks a lot.
Simon Kiss

On 29-Jun-10, at 9:21 PM, Gabor Grothendieck wrote:

> On Tue, Jun 29, 2010 at 6:22 AM, Simon Kiss <sjkiss at gmail.com> wrote:
>> Dear colleagues, particularly academic ones,
>> So I'm creating a Microsoft Word template for myself so that every  
>> time I
>> teach a new course, I don't have to enter in the dates manually for  
>> each
>> class session.
>> I'd like to use an R script that can generate an irregular series  
>> of dates
>> starting from one date (semester begin) to another (semester end)  
>> using an
>> irregular interval in between (Tuesdays and Thursdays, for example).
>> I know that a regular series of dates is no problem, but what about  
>> an
>> irregular series?
>
> Generate all the dates in the range of interest and then pick off the
> Tuesdays and Thursdays:
>
> dd <- seq(as.Date("2010-01-01"), as.Date("2010-12-31"), "day")
> dd[weekdays(dd) %in% c("Tuesday", "Thursday")]

*********************************
Simon J. Kiss, PhD
SSHRC and DAAD Post-Doctoral Fellow
John F. Kennedy Institute of North America Studies
Free University of Berlin
Lansstraße 7-9
14195 Berlin, Germany
Cell: +49 (0)1525-300-2812,
Web: http://www.jfki.fu-berlin.de/index.html