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From |
"Ray Hawkins" <sylviantas@gmail.com> |

To |
<statalist@hsphsun2.harvard.edu> |

Subject |
st: RE: Re: Snowball sampling |

Date |
Tue, 16 Apr 2013 09:19:08 -0500 |

Hello, I posted a similar question a while ago, but have a related question. My data looks the following (without 'keep'), a network data. To generate 'keep', I ran the following code. However, this code covers the first two steps (up to giveid 11) of the whole network starting giveid=17 -> 2 -> 11 -> 18 -> 32 -> 40 -> 16. That is, keep=1 only for giveid=17,2,11. I would like to keep all 7 giveid that are connected. The problem is that I don't know how many steps I need to go to keep all connected id. Or, even if I know, the code will be very complicated to go to 50 or 100 steps, for example. Is there any way I can keep all those connected id starting from a seed id? If Stata cannot handle this problem, then maybe I need to use a social network software? Thank you. Ray Hawkins. gen byte keep=giveid==17 // seed id qui levelsof recid if giveid==17, local(keepers) foreach keeper of local keepers { replace keep=1 if giveid==`keeper' // keep all recid for seed id qui levelsof recid if giveid==`keeper', local(keepers1) foreach keeper of local keepers1 { replace keep=1 if giveid==`keeper' // keep all recid for those who received from giveid=17 and gave to others } } keep if keep==1 giveid recid keep 2 11 1 3 15 0 6 10 0 11 18 1 11 190 1 16 187 0 17 1 1 17 2 1 17 5 1 17 23 1 18 32 0 19 782 0 32 17 0 32 21 0 32 23 0 32 37 0 32 40 0 32 68 0 33 111 0 40 16 0 40 20 0 40 70 0 40 92 0 41 15 0 41 22 0 41 23 0 41 27 0 -----Original Message----- From: owner-statalist@hsphsun2.harvard.edu [mailto:owner-statalist@hsphsun2.harvard.edu] On Behalf Of Joseph Coveney Sent: Friday, March 22, 2013 11:06 PM To: statalist@hsphsun2.harvard.edu Subject: st: Re: Snowball sampling Ray Hawkins wrote: I am working with social network data, but it is too big, so I would like to do snowball sampling. My data look like the following. Can you help me figure out how to keep 'giveid' and corresponding 'recid' for a seed id? For example, giveid=17 is a seed id. So, I would like to keep giveid=17 and all giveid (=recid for giveid=17) = 6, 2, 5, 23, 1, 11, 4, 16, 33, 27, 16 (if exist, of course). Then, for another seed id=32, for example, I would like to repeat the same process to get certain data size. Thank you in advance. -------------------------------------------------------------------------- ------ Not very efficient, but it should work and it has an easy-to-debug one-to-one correspondence with the specifications: * "keep giveid=17" generate byte keep = giveid == 17 * "and all giveid (=recid for giveid=17)" quietly levelsof recid if giveid == 17, local(keepers) quietly foreach keeper of local keepers { replace keep = 1 if giveid == `keeper' } * "repeat the same process" "for another seed id=32" quietly replace keep = 1 if giveid == 32 quietly levelsof recid if giveid == 32, local(keepers) quietly foreach keeper of local keepers { replace keep = 1 if giveid == `keeper' } quietly keep if keep Joseph Coveney * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/faqs/resources/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/faqs/resources/statalist-faq/ * http://www.ats.ucla.edu/stat/stata/

**Follow-Ups**:**st: Re: Snowball sampling***From:*"Joseph Coveney" <stajc2@gmail.com>

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