What I think you need is something along the lines of: matrix(c(sample(3:7), sample(3:7), sample(3:7), sample(3:7), ...), nrow=2)
now, each column are your random pairs. -Aaron On Wed, Mar 9, 2011 at 1:01 PM, Hosack, Michael <mhos...@state.pa.us> wrote: > > -----Original Message----- > > From: r-help-bounces at r-project.org [mailto:r-help-bounces at > r-project.org] > > On Behalf Of Hosack, Michael > > Sent: Wednesday, March 09, 2011 7:34 AM > > To: r-help at R-project.org > > Subject: [R] Complex sampling? > > > > R users, > > > > I am trying to generate a randomized weekday survey schedule that ensures > > even coverage of weekdays in > > the sample, where the distribution of variable DOW is random with respect > > to WEEK. To accomplish this I need > > to randomly sample without replacement two weekdays per week for each of > > 27 weeks (only 5 are shown). > > This seems simple enough, sampling without replacement. > > However, > > I need to sample from a sequence (3:7) that needs to be completely > > depleted and replenished until the > > final selection is made. Here is an example of what I want to do, > > beginning at WEEK 1. I would prefer to do > > this without using a loop, if possible. > > > > sample frame: [3,4,5,6,7] --> [4,5,6] --> [4],[1,2,3,(4),5,6] --> > > [1,2,4,5,6] --> for each WEEK in dataframe > > OK, now you have me completely lost. Sorry, but I have no clue as to what > you just did here. I looks like you are trying to describe some > transformation/algorithm but I don't follow it. > > > > I could not reply to this email because it not been delivered to my inbox, > so I had to copy it from the forum. > I apologize for the confusion, this would take less than a minute to > explain in conversation but an hour > to explain well in print. Two DOW_NUMs will be selected randomly without > replacement from the vector 3:7 for each WEEK. When this vector is reduced > to a single integer that integer will be selected and the vector will be > restored and a single integer will then be selected that differs from the > prior selected integer (i.e. cannot sample the same day twice in the same > week). This process will be repeated until two DOW_NUM have been assigned > for each WEEK. That process is what I attempted to illustrate in my original > message. This is beyond my current coding capabilities. > > > > > > > Randomly sample 2 DOW_NUM without replacement from each WEEK ( () = no > two > > identical DOW_NUM can be sampled > > in the same WEEK) > > > > sample = {3,7}, {5,6}, {4,3}, {1,5}, --> for each WEEK in dataframe > > > > So, are you sampling from [3,4,5,6,7], or [1,2,4,5,6], or ...? Can you > show an 'example' of what you would like to end up given your data below? > > > > > Thanks you, > > > > Mike > > > > > > DATE DOW DOW_NUM WEEK > > 2 2011-05-02 Mon 3 1 > > 3 2011-05-03 Tue 4 1 > > 4 2011-05-04 Wed 5 1 > > 5 2011-05-05 Thu 6 1 > > 6 2011-05-06 Fri 7 1 > > 9 2011-05-09 Mon 3 2 > > 10 2011-05-10 Tue 4 2 > > 11 2011-05-11 Wed 5 2 > > 12 2011-05-12 Thu 6 2 > > 13 2011-05-13 Fri 7 2 > > 16 2011-05-16 Mon 3 3 > > 17 2011-05-17 Tue 4 3 > > 18 2011-05-18 Wed 5 3 > > 19 2011-05-19 Thu 6 3 > > 20 2011-05-20 Fri 7 3 > > 23 2011-05-23 Mon 3 4 > > 24 2011-05-24 Tue 4 4 > > 25 2011-05-25 Wed 5 4 > > 26 2011-05-26 Thu 6 4 > > 27 2011-05-27 Fri 7 4 > > 30 2011-05-30 Mon 3 5 > > 31 2011-05-31 Tue 4 5 > > 32 2011-06-01 Wed 5 5 > > 33 2011-06-02 Thu 6 5 > > 34 2011-06-03 Fri 7 5 > > > > DF <- > > structure(list(DATE = structure(c(15096, 15097, 15098, 15099, > > 15100, 15103, 15104, 15105, 15106, 15107, 15110, 15111, 15112, > > 15113, 15114, 15117, 15118, 15119, 15120, 15121, 15124, 15125, > > 15126, 15127, 15128), class = "Date"), DOW = c("Mon", "Tue", > > "Wed", "Thu", "Fri", "Mon", "Tue", "Wed", "Thu", "Fri", "Mon", > > "Tue", "Wed", "Thu", "Fri", "Mon", "Tue", "Wed", "Thu", "Fri", > > "Mon", "Tue", "Wed", "Thu", "Fri"), DOW_NUM = c(3, 4, 5, 6, 7, > > 3, 4, 5, 6, 7, 3, 4, 5, 6, 7, 3, 4, 5, 6, 7, 3, 4, 5, 6, 7), > > WEEK = c(1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 4, > > 4, 4, 4, 4, 5, 5, 5, 5, 5)), .Names = c("DATE", "DOW", "DOW_NUM", > > "WEEK"), row.names = c(2L, 3L, 4L, 5L, 6L, 9L, 10L, 11L, 12L, > > 13L, 16L, 17L, 18L, 19L, 20L, 23L, 24L, 25L, 26L, 27L, 30L, 31L, > > 32L, 33L, 34L), class = "data.frame") > > > > Dan > > Daniel Nordlund > Bothell, WA USA > > ______________________________________________ > 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. > [[alternative HTML version deleted]] ______________________________________________ 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.
