Here is one way of doing it: > x <- read.table(textConnection("WK TD VARTD PD > DailyVarPD + 28 0.014735 0.0000449 0 0 + 28 0.012421 0.0000449 0 0 + 28 0.014396 0.0000449 71 7005 + 28 0.014898 0.0000449 132 14016 + 28 0.013512 0.0000449 223 32506 + 28 0.013886 0.0000449 224 31287 + 28 0.013778 0.0000449 218 30528 + 29 0.013274 0.0000449 228 34505 + 29 0.013072 0.0000449 224 34531 + 29 0.012518 0.0000449 488 117720 + 29 0.013264 0.0000449 525 119323 + 29 0.013233 0.0000449 80 9134 + 29 0.010194 0.0000449 417 133067 + 29 0.012567 0.0000449 82 10184 + 30 0.014695 0.0000449 413 68893 + 30 0.010634 0.0000449 373 103688 + 30 0.013934 0.0000449 914 272719 + 30 0.014107 0.0000449 213 28473 + 30 0.014339 0.0000449 651 147016 + 30 0.014375 0.0000449 521 102429 + 30 0.016373 0.0000449 979 229104"), header=TRUE) > closeAllConnections() > # daily using your formula > x$newDaily <- with(x, (PD * (1 - TD))/TD + VARTD * ((PD*(1-TD)+ > PD^2*TD))/TD^3) > x WK TD VARTD PD DailyVarPD newDaily 1 28 0.014735 4.49e-05 0 0 0.000 2 28 0.012421 4.49e-05 0 0 0.000 3 28 0.014396 4.49e-05 71 7005 7006.197 4 28 0.014898 4.49e-05 132 14016 14018.783 5 28 0.013512 4.49e-05 223 32506 32514.484 6 28 0.013886 4.49e-05 224 31287 31295.424 7 28 0.013778 4.49e-05 218 30528 30535.647 8 29 0.013274 4.49e-05 228 34505 34514.170 9 29 0.013072 4.49e-05 224 34531 34539.992 10 29 0.012518 4.49e-05 488 117720 117762.642 11 29 0.013264 4.49e-05 525 119323 119365.443 12 29 0.013233 4.49e-05 80 9134 9136.090 13 29 0.010194 4.49e-05 417 133067 133116.531 14 29 0.012567 4.49e-05 82 10184 10186.465 15 30 0.014695 4.49e-05 413 68893 68915.217 16 30 0.010634 4.49e-05 373 103688 103724.478 17 30 0.013934 4.49e-05 914 272719 272829.966 18 30 0.014107 4.49e-05 213 28473 28480.576 19 30 0.014339 4.49e-05 651 147016 147070.746 20 30 0.014375 4.49e-05 521 102429 102464.631 21 30 0.016373 4.49e-05 979 229104 229195.063 > # not sure what you want for weekly, but we can take the averages of the > values > x.wk <- aggregate(x, list(x$WK), mean) > x.wk$var <- with(x.wk, (PD * (1 - TD))/TD + VARTD * ((PD*(1-TD)+ > PD^2*TD))/TD^3) > x.wk Group.1 WK TD VARTD PD DailyVarPD newDaily var 1 28 28 0.01394657 4.49e-05 124.0000 16477.43 16481.51 14340.27 2 29 29 0.01258886 4.49e-05 292.0000 65494.86 65517.33 53548.78 3 30 30 0.01406529 4.49e-05 580.5714 136046.00 136097.24 126432.61 > >
On Feb 16, 2008 11:17 AM, Felipe Carrillo <[EMAIL PROTECTED]> wrote: > Jim: > I actually would like to know how can I estimate Daily > and Weekly Variance for PD using R and not Excel.I > have read about R's variance function but I don't know > how to apply it to PD in my dataset. I hope my > question is clearer. Thanks > > > > > Dear All: > > > Using the Excel formula below I am able to > > estimate > > > daily variance(Daily VarPD)for PD,but I can't > > figure > > > out how to estimate the Weekly variance for PD. > > Any > > > hints? > > > > > > Daily VarPD = (PD * (1 - TD))/TD + VarTD * > > > ((PD*(1-TD)+ PD^2*TD))/TD^3 > > > > > > > > > WK TD VARTD PD Daily > > VarPD > > > 28 0.014735 0.0000449 0 0 > > > 28 0.012421 0.0000449 0 0 > > > 28 0.014396 0.0000449 71 > > 7005 > > > 28 0.014898 0.0000449 132 > > 14016 > > > 28 0.013512 0.0000449 223 > > 32506 > > > 28 0.013886 0.0000449 224 > > 31287 > > > 28 0.013778 0.0000449 218 > > 30528 > > > 29 0.013274 0.0000449 228 > > 34505 > > > 29 0.013072 0.0000449 224 > > 34531 > > > 29 0.012518 0.0000449 488 > > 117720 > > > 29 0.013264 0.0000449 525 > > 119323 > > > 29 0.013233 0.0000449 80 > > 9134 > > > 29 0.010194 0.0000449 417 > > 133067 > > > 29 0.012567 0.0000449 82 > > 10184 > > > 30 0.014695 0.0000449 413 > > 68893 > > > 30 0.010634 0.0000449 373 > > 103688 > > > 30 0.013934 0.0000449 914 > > 272719 > > > 30 0.014107 0.0000449 213 > > 28473 > > > 30 0.014339 0.0000449 651 > > 147016 > > > 30 0.014375 0.0000449 521 > > 102429 > > > 30 0.016373 0.0000449 979 > > 229104 > > > > > > > > > Felipe D. Carrillo > > > Fishery Biologist > > > US Fish & Wildlife Service > > > California, USA > > > > > > > > > > > > > > > ____________________________________________________________________________________ > > > Be a better friend, newshound, and > > > > > > ______________________________________________ > > > 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. > > > > > > > > > -- > > Jim Holtman > > Cincinnati, OH > > +1 513 646 9390 > > > > What is the problem you are trying to solve? > > > > > Felipe D. Carrillo > Fishery Biologist > US Fish & Wildlife Service > California, USA > > > > > ____________________________________________________________________________________ > Never miss a thing. Make Yahoo your home page. > http://www.yahoo.com/r/hs > -- Jim Holtman Cincinnati, OH +1 513 646 9390 What is the problem you are trying to solve? ______________________________________________ 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.