This can of course be done, but before I make any attempt to do it I have to ask: why do you want this?
On Wed, Nov 17, 2010 at 7:08 PM, wangwallace <talentt...@gmail.com> wrote: > > I have another question about drawing samples from a data frame. This might > sound really tricky. Let me use a data frame I have posted earlier as an > example: > > SubID CSE1 CSE2 CSE3 CSE4 WSE1 WSE2 WSE3 WSE4 > 1 6 5 6 2 6 2 2 4 > 2 6 4 7 2 6 6 2 3 > 3 5 5 5 5 5 5 4 5 > 4 5 4 3 4 4 4 5 2 > 5 5 6 7 5 6 4 4 1 > 6 5 4 3 6 4 3 7 3 > 7 3 6 6 3 6 5 2 1 > 8 3 6 6 3 6 5 4 7 > > this data frame have two sets of variables. each set simply represent one > scale. as shown above, the first scale, say CSE, consists of four items: > CSE1, CSE2, CSE3, and CSE4, whereas the second scale, say WSE, also has four > items: WSE1, WSE2, WSE3, WSE4. > the leftmost column lists the subjects' ID. > > I wanna create a new data frame through sampling random numbers from the > data frame above. Below is the structure of the new data frame. > > SubID var var var var > s c c c c > s c c c c > s c w w w > s c w w w > s c w w w > s c w w w > s c w w w > s c w w w > > in the new data frame: > > s= SubID range from 1 to 8 > var= variables > c=CSE numbers > w=WSE numbers > > some rules to construct the new data frame: > > 1. the top two rows have to be filled with CSE numbers; the numbers in the > cells of each row should be randomized. for example, if the first row is an > array of numbers from subject 4, they can follow the order: 4(CSE2), > 5(CSE1), 3(CSE3), and 4(CSE4). Also, the numbers in the second row does not > have to follow the order of the first row. for example, similarly, if the > first row is an array of numbers from subject 4 in the order: 4(CSE2), > 5(CSE1), 3(CSE3), and 4(CSE4), numbers in the second row (assuming it is > from subject 8) does not have to be 6(CSE2), 3(CSE1), 6(CSE3), and 3(CSE4). > numbers in these two rows should be drawn without replacement. > > 2. each of the rest of the rows should include a CSE number in the leftmost > cell and three WSE numbers on the right. At the same time, in each row, the > three WSE numbers on the right have to be only those numbers that are not > corresponding to the CSE number in the leftmost cell. For example, if the > CSE number in the leftmost cell is 4, a CSE2 number from subject 6, the > three WSE numbers on the right side can only be 4(WSE1), 7(WSE3), and > 3(WSE4) from subject 6. > > 3. the numbers in each row can only be drawn from the same subject. Also, > Subjects should be randomized. Specifically, they does have to be in the > following order: > > SubID > 1 > 2 > 3 > 4 > 5 > 6 > 7 > 8 > > they can be: > > SubID > 2 > 8 > 5 > 4 > 1 > 6 > 7 > 3 > > Any ideas? Thanks in advance!! :) > -- > View this message in context: > http://r.789695.n4.nabble.com/New-Sampling-question-tp3047885p3047885.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > 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. > -- Ista Zahn Graduate student University of Rochester Department of Clinical and Social Psychology http://yourpsyche.org ______________________________________________ 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.
