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From |
Fernando Luco <flucoestatalist@gmail.com> |

To |
statalist@hsphsun2.harvard.edu |

Subject |
Re: st: RE: Insert new observation by group |

Date |
Wed, 2 Nov 2011 16:32:43 -0500 |

Thanks Nick. I modified the example before sending it and I didn't change the sums in the text, sorry about that. And thanks about the idea about using expand, I didn't know it was possible. Thanks, Fernando On Wed, Nov 2, 2011 at 4:25 PM, Nick Cox <n.j.cox@durham.ac.uk> wrote: > I don't understand all your requirements. I have 1 + 2 + 2 = 5 (not 6) for group 1 and similarly get a different sum for group 2. > > Also, you don't explain where -ingap- comes from. > > The bit you may be missing most is -expand-. This may give you a start. > > bysort group : gen order = _n > by group: gen last = _n == _N > expand 2 if last > bysort group (order) : replace y = <whatever> if _n == _N > by group : replace x = <something else> if _n == _N > > Nick > n.j.cox@durham.ac.uk > > Fernando Luco > > I'm trying to create a new observation for each group in my data, but > I haven't been able to do so. I tried using -ingap- but didn't work > because > it inserts the new observation at the top of the group or after the > first observation. > My data looks as follows: > > group y x > 1 1 10 > 1 2 10 > 1 2 10 > 2 3 8 > 2 1 8 > > What I want is to insert a new observation at the end of each group, > and this observation must be the difference between "x" (in my case > this is 10 for group one and 8 for group two) and the sum of "y" > (6 for group one and 3 for group two). So, the idea is that the final > dataset should look as follows > > group y x > 1 1 10 > 1 2 10 > 1 2 10 > 1 5 10 > 2 3 8 > 2 1 8 > 2 4 8 > > Any ideas? Thanks, > > Fernando > * > * 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/

**References**:**st: Insert new observation by group***From:*Fernando Luco <flucoestatalist@gmail.com>

**st: RE: Insert new observation by group***From:*Nick Cox <n.j.cox@durham.ac.uk>

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