Notice that only column 19 in your original had the same for the average of the average and every entry had 32 data points.
On Mon, May 24, 2010 at 1:47 PM, jim holtman <jholt...@gmail.com> wrote: > A quick check of you data shows that there are not the same number of > sample in each of the different conditions, therefore trying to take > the average of the averages will not work. > > 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 > 1 32 31 29 30 24 23 31 32 32 31 24 23 29 24 30 26 20 17 32 32 32 31 24 23 > 2 32 32 32 32 24 24 32 32 32 32 24 24 32 32 32 32 24 24 32 32 32 31 24 24 > 3 32 32 32 32 24 23 32 32 32 31 24 23 32 32 32 31 24 24 32 31 32 32 24 24 > 4 31 29 31 29 22 21 31 28 31 29 24 23 29 29 30 26 22 24 32 31 31 30 20 24 > 5 31 32 32 32 24 24 32 31 32 32 24 24 32 32 32 32 24 24 32 32 32 32 24 24 > 6 32 31 32 32 24 24 32 32 32 32 24 24 32 32 32 32 24 24 32 32 32 32 23 24 > 7 32 31 32 31 24 24 32 32 32 32 24 24 32 32 32 32 23 24 32 32 32 32 24 24 > 11 32 32 32 32 24 24 32 32 32 32 24 24 32 32 32 32 24 24 32 32 32 32 24 24 > 12 32 32 32 32 24 24 32 32 31 32 24 24 31 32 32 32 23 23 32 32 32 32 24 24 > 13 32 32 32 32 24 24 32 32 32 32 24 24 32 32 32 32 24 24 32 32 32 32 24 24 > 14 32 32 32 32 24 24 32 32 32 32 24 24 32 32 32 32 24 24 32 32 32 32 24 24 > 15 32 32 32 32 24 24 32 32 32 32 24 24 32 32 32 32 24 24 32 32 32 32 24 24 > 16 32 32 32 32 24 24 32 32 32 32 24 24 32 32 32 31 23 23 32 32 32 31 24 24 > 17 32 32 32 31 24 24 32 32 32 32 24 24 32 32 32 32 24 24 32 32 32 32 24 24 > 18 32 32 32 32 24 24 32 32 32 32 23 24 32 32 32 32 24 24 32 32 32 32 24 24 > 19 32 32 32 32 24 24 32 32 32 32 24 24 32 32 32 32 24 24 32 32 32 32 24 24 > 20 32 32 32 32 24 24 32 32 32 32 24 24 32 32 32 32 24 24 32 32 32 32 24 24 > 21 32 32 32 32 24 24 32 32 32 32 24 24 32 32 32 32 24 24 32 32 32 32 24 24 > 22 32 32 32 32 24 24 32 32 31 32 24 24 32 31 32 32 24 24 32 32 32 32 24 24 > 23 32 32 32 32 24 24 32 32 32 31 24 23 32 32 32 31 24 24 32 32 32 32 24 24 > > > On Mon, May 24, 2010 at 1:29 PM, Ruijie <breakaw...@gmail.com> wrote: >> Thanks for your help jim. I have attached the raw data to see if anyone else >> can replicate my problem. >> >> Correction: i realise my attachment was too large, I have uploaded it to >> another site. The link is: >> http://dl.dropbox.com/u/1443460/List%20-%20Raw%20Data.csv >> >> >> Regards, >> Ruijie (RJ) >> >> -------- >> He who has a why can endure any how. >> >> ~ Friedrich Nietzsche >> >>> >>> >>> On 25 May 2010 00:17, jim holtman <jholt...@gmail.com> wrote: >>> >>>> Are you sure that you have the same number of data points in each of >>>> the summary cells that you show in your csv file that was sent? You >>>> need to provide a reproducible example of all the data so we can see >>>> what you did. The best information I can provide at this point is >>>> that you have a "bug" in your calculations. >>>> >>>> On Mon, May 24, 2010 at 11:10 AM, Ruijie <breakaw...@gmail.com> wrote: >>>> > Noted. >>>> > >>>> > I have attached a list of some data in csv format. >>>> > >>>> > The first column is the SubID and the rest of the column are the mean of >>>> > each condition for the particular subject. >>>> > >>>> > Average 1 is the average computed from each column in the list. >>>> > Average 2 is computed from the raw data of all the data points of a >>>> > condition. >>>> > >>>> > The difference is typically at the 3rd decimal place. If anyone needs >>>> the >>>> > raw data, I could supply it after some clean up. >>>> > >>>> > I suspected round of errors but in all procedures in R, I retained 14 >>>> > significant figures. How would the round off error affect the 3rd >>>> decimal >>>> > place? >>>> > >>>> > Any ideas anyone? >>>> > >>>> > Regards, >>>> > Ruijie (RJ) >>>> > >>>> > -------- >>>> > He who has a why can endure any how. >>>> > >>>> > ~ Friedrich Nietzsche >>>> > >>>> > >>>> > On 24 May 2010 22:47, jim holtman <jholt...@gmail.com> wrote: >>>> >> >>>> >> It is hard to tell what you are doing without data and the results you >>>> >> have gotten so far: >>>> >> >>>> >> PLEASE do read the posting guide >>>> >> http://www.R-project.org/posting-guide.html >>>> >> and provide commented, minimal, self-contained, reproducible code. >>>> >> >>>> >> >>>> >> On Mon, May 24, 2010 at 10:35 AM, Ruijie <breakaw...@gmail.com> wrote: >>>> >> > Hi all, >>>> >> > >>>> >> > here is my situation >>>> >> > >>>> >> > In my experiment, I expose 10 subjects to 24 different conditions of >>>> >> > stimuli. Each condition is exposed to the same subject 3x. >>>> >> > This would make each subject have 24x3=72 data points. All the >>>> subjects >>>> >> > combined would have 72x10=720 data points with each condition having >>>> 30 >>>> >> > datapoints. >>>> >> > >>>> >> > To find the grand average of each condition, I find the average of >>>> all >>>> >> > the >>>> >> > datapoints for a given condition. >>>> >> > >>>> >> > To find the SD for each condition, if I use the raw dataset (720 >>>> >> > datapoints) >>>> >> > it would not reflect the SD across subjects. Therefore, I compute the >>>> >> > average for each condition per subject .i.e. For subject 1, I would >>>> find >>>> >> > the >>>> >> > average of condition 1 (average across 3 trials). and so on. >>>> >> > With the average of each condition per subject, I then compute the >>>> SD. >>>> >> > >>>> >> > Since I computed the average of each condition per subject, >>>> >> > theoretically, >>>> >> > if i average the average of each condition per subject across all >>>> >> > subjects, >>>> >> > the result would be the same as the grand average. >>>> >> > >>>> >> > However, this is not the case when I use R or Excel. regardless of >>>> >> > functions >>>> >> > used. Anyone have any thoughts? >>>> >> > >>>> >> > Regards, >>>> >> > Ruijie (RJ) >>>> >> > >>>> >> > -------- >>>> >> > He who has a why can endure any how. >>>> >> > >>>> >> > ~ Friedrich Nietzsche >>>> >> > >>>> >> > [[alternative HTML version deleted]] >>>> >> > >>>> >> > ______________________________________________ >>>> >> > 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 that you are trying to solve? >>>> > >>>> > >>>> >>>> >>>> >>>> -- >>>> Jim Holtman >>>> Cincinnati, OH >>>> +1 513 646 9390 >>>> >>>> What is the problem that you are trying to solve? >>>> >>> >>> >> >> [[alternative HTML version deleted]] >> >> ______________________________________________ >> 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 that you are trying to solve? > -- Jim Holtman Cincinnati, OH +1 513 646 9390 What is the problem that 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.
