Thank you all. Actually I need set.seed because I have to evaluate the consistency of features selection generated by different models, so I think for this, it's recommended to use the seed.
Warm regards On Tuesday, March 22, 2022, Ebert,Timothy Aaron <teb...@ufl.edu> wrote: > If you are using the program for data analysis then set.seed() is not > necessary unless you are developing a reproducible example. In a standard > analysis it is mostly counter-productive because one should then ask if > your presented results are an artifact of a specific seed that you selected > to get a particular result. However, in cases where you need a reproducible > example, debugging a program, or specific other cases where you might need > the same result with every run of the program then set.seed() is an > essential tool. > Tim > > -----Original Message----- > From: R-help <r-help-boun...@r-project.org> On Behalf Of Jeff Newmiller > Sent: Monday, March 21, 2022 8:41 PM > To: r-help@r-project.org; Neha gupta <neha.bologn...@gmail.com>; r-help > mailing list <r-help@r-project.org> > Subject: Re: [R] How important is set.seed > > [External Email] > > First off, "ML models" do not all use random numbers (for prediction I > would guess very few of them do). Learn and pay attention to what the > functions you are using do. > > Second, if you use random numbers properly and understand the precision > that your specific use case offers, then you don't need to use set.seed. > However, in practice, using set.seed can allow you to temporarily avoid > chasing precision gremlins, or set up specific test cases for testing code, > not results. It is your responsibility to not let this become a crutch... a > randomized simulation that is actually sensitive to the seed is unlikely to > offer an accurate result. > > Where to put set.seed depends a lot on how you are performing your > simulations. In general each process should set it once uniquely at the > beginning, and if you use parallel processing then use the features of your > parallel processing framework to insure that this happens. Beware of > setting all worker processes to use the same seed. > > On March 21, 2022 5:03:30 PM PDT, Neha gupta <neha.bologn...@gmail.com> > wrote: > >Hello everyone > > > >I want to know > > > >(1) In which cases, we need to use set.seed while building ML models? > > > >(2) Which is the exact location we need to put the set.seed function i.e. > >when we split data into train/test sets, or just before we train a model? > > > >Thank you > > > > [[alternative HTML version deleted]] > > > >______________________________________________ > >R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > >https://urldefense.proofpoint.com/v2/url?u=https-3A__stat.ethz.ch_mailm > >an_listinfo_r-2Dhelp&d=DwICAg&c=sJ6xIWYx-zLMB3EPkvcnVg&r=9PEhQh2kVeAsRz > >sn7AkP-g&m=s9osWKJN-zG2VafjXQYCmU_AMS5w3eAtCfeJAwnphAb7ap8kDYfcLwt2jrmf > >0UaX&s=5b117E3OFSf5VyLOctfnrz0rj5B2WyRxpXsq4Y3TRMU&e= > >PLEASE do read the posting guide > >https://urldefense.proofpoint.com/v2/url?u=http-3A__www.R-2Dproject.org > >_posting-2Dguide.html&d=DwICAg&c=sJ6xIWYx-zLMB3EPkvcnVg&r=9PEhQh2kVeAsR > >zsn7AkP-g&m=s9osWKJN-zG2VafjXQYCmU_AMS5w3eAtCfeJAwnphAb7ap8kDYfcLwt2jrm > >f0UaX&s=wI6SycC_C2fno2VfxGg9ObD3Dd1qh6vn56pIvmCcobg&e= > >and provide commented, minimal, self-contained, reproducible code. > > -- > Sent from my phone. Please excuse my brevity. > > ______________________________________________ > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > https://urldefense.proofpoint.com/v2/url?u=https-3A__stat. > ethz.ch_mailman_listinfo_r-2Dhelp&d=DwICAg&c=sJ6xIWYx-zLMB3EPkvcnVg&r= > 9PEhQh2kVeAsRzsn7AkP-g&m=s9osWKJN-zG2VafjXQYCmU_ > AMS5w3eAtCfeJAwnphAb7ap8kDYfcLwt2jrmf0UaX&s=5b117E3OFSf5VyLOctfnrz0rj5B2Wy > RxpXsq4Y3TRMU&e= > PLEASE do read the posting guide https://urldefense.proofpoint. > com/v2/url?u=http-3A__www.R-2Dproject.org_posting-2Dguide. > html&d=DwICAg&c=sJ6xIWYx-zLMB3EPkvcnVg&r=9PEhQh2kVeAsRzsn7AkP-g&m= > s9osWKJN-zG2VafjXQYCmU_AMS5w3eAtCfeJAwnphAb7ap8kDYfcL > wt2jrmf0UaX&s=wI6SycC_C2fno2VfxGg9ObD3Dd1qh6vn56pIvmCcobg&e= > 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.
