st: extract values from kdensity graphic

[mcross@exemail.com.au]

* Hi Statalist,
* I'm a beginner using version 8.
* The following measurements were collected by a machine in my lab...
clear
input sampling_event size
1 94.74
2 94.89
3 94.95
4 94.97
5 95
6 95.05
7 95.08
8 96.11
9 96.22
10 96.24
11 96.27
12 96.27
13 96.27
14 96.32
15 96.34
16 97.19
17 97.26
18 97.26
19 97.32
20 97.34
21 97.39
22 98.41
23 100.62
24 100.69
25 100.69
26 100.76
27 100.76
28 100.76
29 100.84
30 100.91
end
list
twoway (scatter size sampling_event)

* My aim is to class these size values into categories (5 categories in
the example shown).
* kdensity will generate the following graphic...

kdensity size , w(0.1) n(30)

* The troughs of this graphic are a good way to define the bounds of each
category.
* Category_4, for example would include all size values larger than 98 and
less than 99.
* I'd like to extract these trough points as a kdensity post-estimation
and output them as a new variable.
* Is this possible?

* Look forward to any advice the list has to offer.

* Cheers,

* Mike.


*
*   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/