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# Re: st: Problem selecting data range within a variable

 From Nick Cox To statalist@hsphsun2.harvard.edu Subject Re: st: Problem selecting data range within a variable Date Thu, 19 Jul 2012 11:15:52 +0100

```Here are some simple idea:

. sysuse auto, clear
(1978 Automobile Data)

. xtile pq = price, nq(10)

. tab pq

10 |
quantiles |
of price |      Freq.     Percent        Cum.
------------+-----------------------------------
1 |          8       10.81       10.81
2 |          7        9.46       20.27
3 |          8       10.81       31.08
4 |          7        9.46       40.54
5 |          7        9.46       50.00
6 |          8       10.81       60.81
7 |          7        9.46       70.27
8 |          8       10.81       81.08
9 |          7        9.46       90.54
10 |          7        9.46      100.00
------------+-----------------------------------
Total |         74      100.00

. tab pq if pq == 1 | pq == 10, su(weight)

10 |
quantiles |      Summary of Weight (lbs.)
of price |        Mean   Std. Dev.       Freq.
------------+------------------------------------
1 |    2,373.75   370.98084           8
10 |   4,024.286   628.24775           7
------------+------------------------------------
Total |       3,144   982.05906          15

Nick

On Thu, Jul 19, 2012 at 10:57 AM, WAREHAM H.M.
<helen.wareham@durham.ac.uk> wrote:
> I have some data and one of the variables I have put into deciles.  For an analysis I want to compare variables from the top 10% (decile 1) and the bottom 10% (decile 10) of the data but I can't work out how to get Stata to do that.
>
> I'm very new to Stata so the more simple the explanation the better.
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```