[R] creating conditional means

[Moshe Olshansky]

Following Gabor's suggestion, if x is your data.frame
you can do 

y <- x[x$month %in% c(3,4,5),]
aggregate(y[,4:6],list(y$hour),mean)

--- Sherri Heck <sheck at ucar.edu> wrote:

> Hi Gabor,
> 
> Thank you for your help.  I think I need to clarify
> a bit more.  I am 
> trying to say
> 
> average all 2pms for months march + april + may (for
> example). I hope this is clearer.  
> 
> here's a larger subset of my data set:
> 
> year, month, hour, co2(ppm), num1,num2
> 
> 2006 1 0 384.2055 14 14
> 2006 1 1 384.0304 14 14
> 2006 1 2 383.9672 14 14
> 2006 1 3 383.8452 14 14
> 2006 1 4 383.8594 14 14
> 2006 1 5 383.7318 14 14
> 2006 1 6 383.6439 14 14
> 2006 1 7 383.7019 14 14
> 2006 1 8 383.7487 14 14
> 2006 1 9 383.8376 14 14
> 2006 1 10 383.8684 14 14
> 2006 1 11 383.8301 14 14
> 2006 1 12 383.8058 14 14
> 2006 1 13 383.9419 14 14
> 2006 1 14 383.7876 14 14
> 2006 1 15 383.7744 14 14
> 2006 1 16 383.8566 14 14
> 2006 1 17 384.1014 14 14
> 2006 1 18 384.1312 14 14
> 2006 1 19 384.1551 14 14
> 2006 1 20 384.099 14 14
> 2006 1 21 384.1408 14 14
> 2006 1 22 384.3637 14 14
> 2006 1 23 384.1491 14 14
> 2006 2 0 384.7082 27 27
> 2006 2 1 384.6139 27 27
> 2006 2 2 384.7453 26 26
> 2006 2 3 384.9224 28 28
> 2006 2 4 384.8581 28 28
> 2006 2 5 384.9208 28 28
> 2006 2 6 384.9086 28 28
> 2006 2 7 384.837 28 28
> 2006 2 8 384.6163 27 27
> 2006 2 9 384.7406 28 28
> 2006 2 10 384.7468 28 28
> 2006 2 11 384.6992 28 28
> 2006 2 12 384.6388 28 28
> 2006 2 13 384.6346 28 28
> 2006 2 14 384.6037 28 28
> 2006 2 15 384.5295 28 28
> 2006 2 16 384.5654 28 28
> 2006 2 17 384.6466 28 28
> 2006 2 18 384.6344 28 28
> 2006 2 19 384.5911 28 28
> 2006 2 20 384.6084 28 28
> 2006 2 21 384.6318 28 28
> 2006 2 22 384.6181 27 27
> 2006 2 23 384.6087 27 27
> 
> 
> thanks you again for your assistance-
> 
> s.heck
> 
> 
> Gabor Grothendieck wrote:
> > Try aggregate:
> >
> >
> > Lines <- "Year Month Hour co2 num1 num2
> >  2006   11    0 383.3709   28   28
> >  2006   11    1 383.3709   28   28
> >  2006   11    2 383.3709   28   28
> >  2006   11    3 383.3709   28   28
> >  2006   11    4 383.3709   28   28
> >  2006   11    5 383.3709   28   28
> >  2006   11    6 383.3709   28   28
> >  2006   11    7 383.3709   28   28
> >  2006   11    8 383.3709   28   28
> >  2006   11    9 383.3709   27   27
> >  2006   11   10 383.3709   28   28
> > "
> > DF <- read.table(textConnection(Lines), header =
> TRUE)
> > aggregate(DF[4:6],
> >    with(DF, data.frame(Year, Qtr = (Month - 1) %/%
> 3 + 1, Hour)),
> >    mean)
> >
> > On Dec 1, 2007 3:57 PM, Sherri Heck
> <sheck at ucar.edu> wrote:
> >   
> >> Hi all-
> >>
> >> I have a dataset (year, month, hour, co2(ppm),
> num1,num2)
> >>
> >>
> >> [49,] 2006   11    0 383.3709   28   28
> >> [50,] 2006   11    1 383.3709   28   28
> >> [51,] 2006   11    2 383.3709   28   28
> >> [52,] 2006   11    3 383.3709   28   28
> >> [53,] 2006   11    4 383.3709   28   28
> >> [54,] 2006   11    5 383.3709   28   28
> >> [55,] 2006   11    6 383.3709   28   28
> >> [56,] 2006   11    7 383.3709   28   28
> >> [57,] 2006   11    8 383.3709   28   28
> >> [58,] 2006   11    9 383.3709   27   27
> >> [59,] 2006   11   10 383.3709   28   28
> >>
> >> that repeats in this style for each month.  I
> would like to compute the
> >> mean for each hour in three month intervals.
> >> i.e.  average all 2pms for each day for months
> march, april and may. and
> >> then do this for each hour interval.
> >> i have been messing around with 'for loops' but
> can't seem to get the
> >> output I want.
> >>
> >> thanks in advance for any help-
> >>
> >> s.heck
> >> CU, Boulder
> >>
> >> ______________________________________________
> >> R-help at 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.
> >>
> >>
> 
> ______________________________________________
> R-help at 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.
>