Re: st: Creating a second output data set

[Roger Newson <r.newson@imperial.ac.uk>]

-postfile- will still work if there is an existing dataset in the 
memory. However, the new dataset will be built in a file.

Best wishes

Roger


Roger B Newson BSc MSc DPhil
Lecturer in Medical Statistics
Respiratory Epidemiology and Public Health Group
National Heart and Lung Institute
Imperial College London
Royal Brompton Campus
Room 33, Emmanuel Kaye Building
1B Manresa Road
London SW3 6LR
UNITED KINGDOM
Tel: +44 (0)20 7352 8121 ext 3381
Fax: +44 (0)20 7351 8322
Email: r.newson@imperial.ac.uk
Web page: http://www.imperial.ac.uk/nhli/r.newson/
Departmental Web page:
http://www1.imperial.ac.uk/medicine/about/divisions/nhli/respiration/popgenetics/reph/

Opinions expressed are those of the author, not of the institution.

On 07/09/2011 14:40, Bryan Sayer wrote:
> -postfile- will post my results, but my reading of how it works seems to
> indicate that my original data set cannot be open at the same time. The
> examples appear to me to clear the existing data set from memory.
>
> Admittedly, this is without me having tried anything yet, but am I not
> reading it correctly?
>
> What I need to do is a double loop through the input data set,
> outputting a record on each iteration of each loop. So I need the input
> data set open in memory, and a second file to post the results to.
>
> Are there any examples of something similar?
>
> Thanks!
>
> Bryan Sayer
> Monday to Friday, 8:30 to 5:00
> Phone: (614) 442-7369
> FAX: (614) 442-7329
> BSayer@chrr.osu.edu
>
>
> On 9/6/2011 4:58 PM, Roger Newson wrote:
> > I think you are looking for the -postfile- utility. In Stata, type
> >
> > help postfile
> >
> > to find out more.
> >
> > HTH.
> >
> > Best wishes
> >
> > Roger
> >
> >
> > Roger B Newson BSc MSc DPhil
> > Lecturer in Medical Statistics
> > Respiratory Epidemiology and Public Health Group
> > National Heart and Lung Institute
> > Imperial College London
> > Royal Brompton Campus
> > Room 33, Emmanuel Kaye Building
> > 1B Manresa Road
> > London SW3 6LR
> > UNITED KINGDOM
> > Tel: +44 (0)20 7352 8121 ext 3381
> > Fax: +44 (0)20 7351 8322
> > Email: r.newson@imperial.ac.uk
> > Web page: http://www.imperial.ac.uk/nhli/r.newson/
> > Departmental Web page:
> > http://www1.imperial.ac.uk/medicine/about/divisions/nhli/respiration/popgenetics/reph/
> >
> >
> >
> > Opinions expressed are those of the author, not of the institution.
> >
> > On 06/09/2011 21:53, Bryan Sayer wrote:
> > > I need to create an output data set that will differ in the content and
> > > number of observations from the input file. The observations will be
> > > created one at a time, based on the input data set.
> > >
> > > Specifically, I am creating all combinations of N objects taken two at a
> > > time. I will probably also do permutations.
> > >
> > > The input data set (to start with) consists of N records with two
> > > variables, the primary sampling unit (PSU) and a size variable
> > > associated with the PSU (a count variable). I want to create two output
> > > data sets. One is each combination of PSU with the associated joint
> > > probability. The second has the same structure as the input data set but
> > > includes the marginal probability, calculated as the sum of the joint
> > > probabilities associated with the PSU (which are accumulated as each
> > > combination is created).
> > >
> > > The part I am stuck on is how to output the data set of combinations.
> > > Can someone point me to a program that outputs a file as calculations
> > > are made?
> > >
> > > (For those interested, this is for probability proportional to size
> > > (PPS) sampling. See, for example, Levy and Lemeshow "Sampling of
> > > Populations, chapter 11).
> > >
> > > Here is an example of one stratum:
> > >
> > > Input data set (with marginal probability added)
> > >
> > > District Size pi(i)
> > > LUWEERO 12,466 0.916858
> > > KAMPALA 3,459 0.542857
> > > TORORO 2,815 0.448739
> > > KAMULI 549 0.091546
> > > Total 19,289
> > >
> > >
> > > Output data set:
> > >
> > > COMBINATIONS pi(I,j)
> > > LUWEERO,KAMPALA 0.468854
> > > LUWEERO,TORORO 0.377069
> > > LUWEERO,KAMULI 0.070934
> > > KAMPALA,TORORO 0.062531
> > > KAMPALA,KAMULI 0.011473
> > > TORORO,KAMULI 0.009139
> > *
> > * For searches and help try:
> > * http://www.stata.com/help.cgi?search
> > * http://www.stata.com/support/statalist/faq
> > * http://www.ats.ucla.edu/stat/stata/
> *
> * For searches and help try:
> * http://www.stata.com/help.cgi?search
> * http://www.stata.com/support/statalist/faq
> * http://www.ats.ucla.edu/stat/stata/
*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/