Hi Avi: good morning Again, many thanks to all of you. I appreciate all what you are doing. You are good. I did it in Minitab. It cost me a little bit more time, but it is okay.
It was a little bit confusing for me to do it in R. Because in *Step 1: *I have to select a random sample of size n=204 (say) out of N=700 (say). Then in Step 2: I have to allocate the 204 randomly selected obs. into three groups of equal sample sizes. Again, thank you very much, and sorry if I bothered you. with many thanks abou ______________________ *AbouEl-Makarim Aboueissa, PhD* *Professor, Statistics and Data Science* *Graduate Coordinator* *Department of Mathematics and Statistics* *University of Southern Maine* On Thu, Sep 2, 2021 at 10:42 PM Avi Gross via R-help <r-help@r-project.org> wrote: > Abou, > > > > I am not trying to be negative. Assuming you are a professor of > Statistics, your request seems odd as what you are asking about is very > routine in much of statistical work where you want to make a model or > something using just part of your data and need to reserve some to check if > you perhaps trained an algorithm too much for the original data used. > > > > A simple online search before asking questions here is appreciated. I did > a quick search for something like “R split data into three parts” and see > several applicable answers. > > > > There are people on this forum who actually get paid to do nontrivial > tasks and do not mind help in spots but feel sort of used if expected to > write a serious amount of code and perhaps then be asked to redo it with > more bells and whistles added. A recent badly phrased request comes to mind > where several of us provided and answer only to find out it was for a > different scenario, … > > > > So let me continue with a serious answer. May we assume you KNOW how to > read the data in to something like a data.frame? If so, and if you see no > need or value in doing this the hard way, then your question could have > been to ask if there is an R built-in function or perhaps a pacjkage > already set to solve it quickly. Again, a simple online search can do > wonders. Here, for example is a package called caret and this page > discusses spliutting data multiple ways: > > > > https://topepo.github.io/caret/data-splitting.html > > > > There are other such pages suggesting how to do it using base R. > > > > Here is one that gives an example on how to make three unequal partitions: > > > > inds <- partition(iris$Sepal.Length, p = c(train = 0.6, valid = 0.2, test > = 0.2)) > > > > > > There is more to do below but in the above, you would use whatever names > you want instead of train/valid/test and set all three to 0.33 and so on. > > > > I repeat, that what you want to do strikes some of us as a fairly routine > thing to do and lots of people have written how they have done it and you > can pick and choose, or redo it on your own. If what you have is a homework > assignment, the appropriate thing is to have you learn to use some > technique yourself and perhaps get minor help when it fails. But if you > will be doing this regularly, use of some packages is highly valuable. > > > > Good Luck. > > > > > > > > > > > > From: AbouEl-Makarim Aboueissa <abouelmakarim1...@gmail.com> > Sent: Thursday, September 2, 2021 9:51 PM > To: Avi Gross <avigr...@verizon.net> > Cc: R mailing list <r-help@r-project.org> > Subject: Re: [R] Splitting a data column randomly into 3 groups > > > > Sorry, please forget about it. I believe that I am very serious when I > posted my question. > > > > with thanks > > abou > > > ______________________ > > AbouEl-Makarim Aboueissa, PhD > > > > Professor, Statistics and Data Science > > Graduate Coordinator > > Department of Mathematics and Statistics > > University of Southern Maine > > > > > > > > On Thu, Sep 2, 2021 at 9:42 PM Avi Gross via R-help <r-help@r-project.org > <mailto:r-help@r-project.org> > wrote: > > What is stopping you Abou? > > Some of us here start wondering if we have better things to do than > homework for others. Help is supposed to be after they try and encounter > issues that we may help with. > > So think about your problem. You supplied data in a file that is NOT in > CSV format but is in Tab separated format. > > You need to get it in to your program and store it in something. It looks > like you have 204 items so 1/3 of those would be exactly 68. > > So if your data is in an object like a vector or data.frame, you want to > choose random number between 1 and 204. How do you do that? You need 1/3 of > the length of the object items, in your case 68. > > Now extract the items with those indices into say A1. Extract all the > rest into a temporary item. > > Make another 68 random indices, with no overlap, and copy those items into > A2 and the ones that do not have those into A3 and you are sort of done, > other than some cleanup or whatever. > > There are many ways to do the above and I am sure packages too. > > But since you have made no visible effort, I personally am not going to > pick anything in particular. > > Had you shown some text and code along the lines of the above and just > wanted to know how to copy just the ones that were not selected, we could > easily ... > > > -----Original Message----- > From: R-help <r-help-boun...@r-project.org <mailto: > r-help-boun...@r-project.org> > On Behalf Of AbouEl-Makarim Aboueissa > Sent: Thursday, September 2, 2021 9:30 PM > To: R mailing list <r-help@r-project.org <mailto:r-help@r-project.org> > > Subject: [R] Splitting a data column randomly into 3 groups > > Dear All: > > How to split a column data *randomly* into three groups. Please see the > attached data. I need to split column #2 titled "Data" > > with many thanks > abou > ______________________ > > > *AbouEl-Makarim Aboueissa, PhD* > > *Professor, Statistics and Data Science* *Graduate Coordinator* > > *Department of Mathematics and Statistics* *University of Southern Maine* > > ______________________________________________ > R-help@r-project.org <mailto:R-help@r-project.org> mailing list -- To > UNSUBSCRIBE and more, see > 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 -- To UNSUBSCRIBE and more, see > 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 -- To UNSUBSCRIBE and more, see 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.
