Notice: On April 23, 2014, Statalist moved from an email list to a forum, based at statalist.org.

# Re: st: Residual Plot help

 From Maarten buis To statalist@hsphsun2.harvard.edu Subject Re: st: Residual Plot help Date Tue, 28 Sep 2010 09:02:53 +0000 (GMT)

```--- On Tue, 28/9/10, Hobst wrote:
> I run this regression
>
> xtmixed y x1 x2 x3 || brand: || _all: R.model || datevar:, mle
>
> then predict the residuals
>
> predict bd md qt, reffects
>
> then i somehow plotted this graph:
> http://img521.imageshack.us/img521/7478/randominterceptsbybrand.png
>
> but now i dont know anymore how i got this graph... very
> stupid, i unfortuately deleted the do-file.

One thing I would change about that graph is the sort order of your
brands: The aim of such a graph as a diagnostic tool is to spot
patterns in the residual and your are much more likely to see such
patterns if you sort on the residual rather than on alphabetical
order. You can do that using the egen function -axis()-. You can
get that by typing in Stata: -ssc install egenmore-. After that you
can create your graph, as in this example:

*-------------------- begin example -------------------------
webuse productivity, clear
// there are no value labels attached to this dataset,
// so I am only guessing...
label define region 1 "New England"        ///
2 "Mid-Atlantic"       ///
3 "East North Central" ///
4 "West North Central" ///
5 "South Atlantic"     ///
6 "East South Central" ///
7 "West South Central" ///
8 "Mountain"           ///
9 "Pacific"
label value region region

xtmixed gsp private emp hwy water other unemp ///
|| region: || state:, mle
predict u*, reffects

bys region (u1) : gen byte mark = _n==1
egen axis = axis(u1), label(region)

twoway bar u1 axis if mark, horizontal ylab(1/9, valuel)
*--------------------- end example -----------------------

Hope this helps,
Maarten

--------------------------
Maarten L. Buis
Institut fuer Soziologie
Universitaet Tuebingen
Wilhelmstrasse 36
72074 Tuebingen
Germany

http://www.maartenbuis.nl
--------------------------

*
*   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/
```