Notice: On April 23, 2014, Statalist moved from an email list to a forum, based at statalist.org.
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
st: how to force cutpoint in xtile
From
"Skiles, Martha Priedeman" <[email protected]>
To
"[email protected]" <[email protected]>
Subject
st: how to force cutpoint in xtile
Date
Mon, 25 Jun 2012 21:21:27 +0000
Hi,
I've used -xtile- in Stata 11 successfully, but am having difficulty with it in Stata 12. I have the following variable "S0D0_links" which I'd like to quintile (5 groups), but the -xtile- function is not creating groups where I would expect. Per below, I expected the first quintile to break at 17.3 cumulative percent rather than 37.3. Can I force the cutpoint to be either closest to my 20/40/60/80/100 quintiles or always <20/<40/<60/etc?
I am able to force it by using "cumul" to generate a cumulative percent, and then write code using "ceil(5*cumpercent)" but I hope there's a better option. My preference is to have the cutpoint create quintiles as close to 20/40/60/etc as possible.
Thank you,
Martha Skiles
LOG:
tab S0D0_links
S0D0_links | Freq. Percent Cum.
------------+-----------------------------------
11 | 11 5.95 5.95
12 | 4 2.16 8.11
13 | 17 9.19 17.30
14 | 37 20.00 37.30
15 | 7 3.78 41.08
16 | 27 14.59 55.68
17 | 13 7.03 62.70
18 | 5 2.70 65.41
19 | 14 7.57 72.97
20 | 11 5.95 78.92
21 | 23 12.43 91.35
27 | 16 8.65 100.00
------------+-----------------------------------
Total | 185 100.00
. xtile Q5=S0D0_links, nq(5)
. tab Q5
5 quantiles |
of |
S0D0_links | Freq. Percent Cum.
------------+-----------------------------------
1 | 69 37.30 37.30
2 | 7 3.78 41.08
3 | 40 21.62 62.70
4 | 53 28.65 91.35
5 | 16 8.65 100.00
------------+-----------------------------------
Total | 185 100.00
*
* 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/