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From |
Steven Samuels <sjsamuels@gmail.com> |

To |
statalist@hsphsun2.harvard.edu |

Subject |
Re: st: sampling program help |

Date |
Wed, 19 Jan 2011 23:24:05 -0500 |

Steve Steven J. Samuels sjsamuels@gmail.com 18 Cantine's Island Saugerties NY 12477 USA Voice: 845-246-0774 Fax: 206-202-4783 On Jan 5, 2011, at 11:34 AM, george joseph wrote: Dear Staz, Thank you for your help. But still, I need to use the prone_flood variable in allocating the sansads in a particular manner. Let me try to explain more clearly as I made a mistake in my explanation in the previous mail. Now we have the sample size to be drawn from each category (1-4. given by the generated samplesize variable) Now the issue of alocation based on prone_flood variable comes in. The prone_flood variable is coded 1-4 and more weight should be given to 4 then 3 and then 2 and then 1. We need to choose in such a way that from each GP, those with higher codes are selected first. that is So, from each GP, the sansads should be selected as follows based on the prone_flood variable. If samplesize is 4, select 2 sansands from those which are coded 4 (prone_flood variable) and one each from those sansads which are coded 3 and 2. If the samplesize is 3, select 2 from those which are coded 4 and 1 from those which are coded 3 . If the samplesize is 2, select 2 from those which are coded 4 If the samplesize is 1, select 1 from those which are coded 4. However, the problem arises when one particular category of sansads say those coded 4 (prone_flood variable) are absent.Ideally we should go to the next category coded 3, choose 2 sansads from them and then choose one each from those coded 2 and 1 respectively. Any help on this problem will be really appreciated. Thanks. George For each GP, the procedure is as follows: If the samplesize is 1, we should select 1 sansad from the GP from those sansads which are coded 4 based on prone_flood variable. If none is coded 4, we should select one sansad which is coded 3 from among those which are coded 3. If none is coded 3, we should select one sansad which is coded 2 from among those which are coded 2. And finally, If none is coded 2, we should select one sansad which is coded 1 from among those which are coded 1. To continue,: If the samplesize is 4, we should select 2 sansads from the GP from those sansads which are coded 4 based on prone_flood variable. If none is coded 4, we should select two sansads which is coded 3 from among those which are coded 3. If none is coded 3, we should select two sansads which is coded 2 from among those which are coded 2. And finally, If none is coded 2, we should select all four sansads which is coded 1 from among those which are coded 1.

This is a starting point (it ignores the prone_flood variable, as I could not understand how you use it):recode tot_sansad (8/12=1) (13/14=2) (15/16=3) (17/20=4),gen( samplesize)generate rnd = uniform() bysort gp (rnd) : gen byte tosample = (_n <= samplesize) keep if tosampleOn Tue, Jan 4, 2011 at 3:45 PM, george joseph <gjosephresearch@gmail.com> wrote:Hi, I would like to have your help with writing a program to resolve the following sampling issue I have I have data on 223 sansads ( sansad_id) in 19 GPs . The variable prone_flood_cyclone (1-4) indicates the strength of floods and cyclones in the sansads and tot_sansads indicates the total number of sansads in each GP. I would like to draw a sample of 55 sansads in the following manner. 1) The sample should contain sansads from all 19 GPS 2) If the total number of sansads (tot_sansads) in a GP is less than 12, we should draw one sansad, if tot_sansads is between 13 and 14, we should draw 2 sansads, if tot_sansads is between 15 and 16, we should draw 3 sansads, and if tot_sansads is between 17 and 20, we should draw 4 sansads. The following is the METHOD OF ALLOCATION of the number of SANSADs in each of the GPs giving OVER-WEIGHTAGE to SANSADs Prone to floods, cyclones etc. If the Total number of SANSADs in one GP :8-12 Number of SANSADs to be selected : 1 Method of Allocation ( based on ne_flood_cyclone) 1 to be selected from Code’4 ‘. If Code 4 is ‘NIL’, than 1from Code ‘3’. If Code 3 is also’ NIL’, then 1 from Code’2’. IfCode2 is also ‘NIL’, then 1from Code ‘1’. if Total number of SANSADs in one GP :13-14 Number of SANSADs to be selected : 2 Method of Allocation ( based on prone_flood_cyclone) 1 from Code ‘4’+from Code’3’ – otherwise, follow the sequence as in sl.1. if Total number of SANSADs in one GP :15-16 Number of SANSADs to be selected : 3 Method of Allocation ( based on prone_flood_cyclone) 1from Code’4’ +1from Code’3’+1 from Code’2’- otherwise, follow the sequence as in sl.1. and if Total number of SANSADs in one GP :17-20 Number of SANSADs to be selected : 4 Method of Allocation ( based on prone_flood_cyclone) 2from Code’4’+1 from Code’3’+ 1from Code’2’ - otherwise, follow the sequence as in sl.1. Could you let me know how I can do this which can be replicated . Thanks. George * * 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/-- Stas Kolenikov, also found at http://stas.kolenikov.name Small print: I use this email account for mailing lists only. * * 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: sampling program help***From:*george joseph <gjosephresearch@gmail.com>

**Re: st: sampling program help***From:*Stas Kolenikov <skolenik@gmail.com>

**Re: st: sampling program help***From:*george joseph <gjosephresearch@gmail.com>

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