[R] Central limit theorem

[Ranjan Maitra]

Perhaps, we should endeavor not to provide any kind of help for
such homework problems, especially to untraceable e-mail addresses
(such as gmail, hotmail, yahoo and the like)? After all, conceptualizing
a solution before writing R code is very much a part of the learning
process, no?

Ranjan

On Sun, 14 Aug 2011 17:57:38 -0500 Dennis Murphy <djmuser at gmail.com>
wrote:

> Hi:
> 
> This definitely sounds like a homework problem but it's very easy to
> do in R if you think about it the right way.
> 
> (1) Generate a matrix of random numbers. This is easier than it looks,
> since you can generate a long vector of random numbers and then
> reshape it into a matrix. Typically, a row corresponds to a single
> random sample, so that should tell you how many columns you need; the
> number of samples tells you the number of rows. Type ?rpois at the R
> prompt to see its help page. If necessary, also read the result of
> ?matrix.
> (2) See the help page of the function rowMeans(). Run it on your
> matrix; it will return a vector.
> (3) Plot the histogram. See ?hist
> (4) Read the Posting Guide, which is linked at the bottom of this
> e-mail, and pay attention to the policy on homework questions. (This
> should be point (0), but I'm being pragmatic.)
> 
> Dennis
> 
> On Sun, Aug 14, 2011 at 6:16 AM, maggy yan <kiotoqq at googlemail.com> wrote:
> > my data looks like this:
> >
> >         PM10       Ref   UZ     JZ         WT   RH   FT   WR
> > 1   10.973195  4.338874 nein Winter   Dienstag   ja nein West
> > 2    6.381684  2.250446 nein Sommer    Sonntag nein   ja  Süd
> > 3   62.586512 66.304869   ja Sommer    Sonntag nein nein  Ost
> > 4    5.590101  8.526152   ja Sommer Donnerstag nein nein Nord
> > 5   30.925054 16.073091 nein Winter    Sonntag nein nein  Ost
> > 6   10.750567  2.285075 nein Winter   Mittwoch nein nein  Süd
> > 7   39.118316 17.128691   ja Sommer    Sonntag nein nein  Ost
> > 8    9.327564  7.038572   ja Sommer     Montag nein nein Nord
> > 9   52.271744 15.021977 nein Winter     Montag nein nein  Ost
> > 10  27.388416 22.449102   ja Sommer     Montag nein nein  Ost
> > 11   6.460829  4.486329   ja Winter    Samstag nein nein  Süd
> > 12   5.937690 10.247768   ja Sommer    Sonntag nein nein Nord
> > 13  14.004685  5.155790 nein Winter    Sonntag nein nein Nord
> > 14  12.244333  7.063825   ja Sommer   Mittwoch nein   ja Nord
> > 15  35.195541 12.148438 nein Winter     Montag nein nein  Ost
> > .
> > .
> > .
> > .
> > til 200
> > now I should illustrate the Central limit theorem with my data. I need to
> > make 80 times the arithmetic means of each of the 100 poisson distributet
> > random numbers with an expected value 7.
> > the hint says I need a metrices first which includes all of the 8000 values.
> > but I have no idea where the 8000 values are and how to make the matrices.
> > please help me
> >
> >        [[alternative HTML version deleted]]
> >
> >
> > ______________________________________________
> > 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.
>