Hi Ogbos, If we assume that you have a 3 column data frame named oodf, how about:
oodf[,4]<-floor((cumsum(oodf[,1])-1)/28) col2means<-by(oodf[,2],oodf[,4],mean) col3means<-by(oodf[,3],oodf[,4],mean) Jim On Wed, Nov 28, 2018 at 2:06 PM Ogbos Okike <giftedlife2...@gmail.com> wrote: > > Dear List, > I have three data-column data. The data is of the form: > 1 8590 12516 > 2 8641 98143 > 3 8705 98916 > 4 8750 89911 > 5 8685 104835 > 6 8629 121963 > 7 8676 77655 > 1 8577 81081 > 2 8593 83385 > 3 8642 112164 > 4 8708 103684 > 5 8622 83982 > 6 8593 75944 > 7 8600 97036 > 1 8650 104911 > 2 8730 114098 > 3 8731 99421 > 4 8715 85707 > 5 8717 81273 > 6 8739 106462 > 7 8684 110635 > 1 8713 105214 > 2 8771 92456 > 3 8759 109270 > 4 8762 99150 > 5 8730 77306 > 6 8780 86324 > 7 8804 90214 > 1 8797 99894 > 2 8863 95177 > 3 8873 95910 > 4 8827 108511 > 5 8806 115636 > 6 8869 85542 > 7 8854 111018 > 1 8571 93247 > 2 8533 85105 > 3 8553 114725 > 4 8561 122195 > 5 8532 100945 > 6 8560 108552 > 7 8634 108707 > 1 8646 117420 > 2 8633 113823 > 3 8680 82763 > 4 8765 121072 > 5 8756 89835 > 6 8750 104578 > 7 8790 88429 > > I wish to calculate average of the second and third columns based on the > first column for each repeated 7 days. The length of the data is 1442. That > is 206 by 7. So I should arrive at 207 data points for each of the two > columns after calculating the mean of each group 1-7. > > I have both tried factor/tapply and aggregate functions but seem not to be > making progress. > > Thank you very much for your idea. > > Best wishes > Ogbos > > [[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. ______________________________________________ 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.