Many thanks
Don Spady
----- Original Message -----
From: "Steichen, Thomas" <[email protected]>
To: <[email protected]>
Sent: Friday, October 11, 2002 10:06
Subject: st: RE: percentiles
Don Spady writes:
> I am trying to use the command "pctile" to get percentiles
> of the values in a variable. The values are individual ages.
> I have used the commands:
> pctile pct=age
> pctile pct=age, genp(pctAge)
> but when I run it and then list the first 10 instances I get
>
> . list pct age in 1/10
>
> pct age
> 1. 9 14
> 2. . 17
> 3. . 1
> 4. . 14
> 5. . 5
> 6. . 12
> 7. . 14
> 8. . 7
> 9. . 9
> 10. . 0
>
> The ages run from 0 to 17 and are fairly evenly distributed.
> ?? Why don't I get any values in the pct column and what does
> the '9' mean.
9 is the median.
-pctile- splits the data into k=2 groups unless you specify the
-nquantiles()- option and reports the cutpoints for k-1 groups
in the new variable (pct - in your case). With two groups, the
cutpoint is the median. -genp()- specifies the variable that
contains the percentages in the two groups.
Tom
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