Bookmark and Share

Notice: On March 31, it was announced that Statalist is moving from an email list to a forum. The old list will shut down at the end of May, and its replacement, statalist.org is already up and running.


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: st: RE: query on testing uniform distributions


From   Maarten Buis <maartenlbuis@gmail.com>
To   statalist@hsphsun2.harvard.edu
Subject   Re: st: RE: query on testing uniform distributions
Date   Wed, 2 Nov 2011 08:35:20 +0100

On Tue, Nov 1, 2011 at 6:00 PM, Sergio Salis <S.Salis@psi.org.uk> wrote:
> I understand that to check whether employment_start_dates follow a uniform distribution I can also use the ksmirnov test. It is not clear to me what the command -ksmirnov hazel=hazel- actually does (so I would appreciate if you could provide some further explanation on this).

To quote the helpfile of -ksmirnov-: "varname is the variable whose
distribution is being tested, and exp must evaluate to the
corresponding (theoretical) cumulative."


>However, if employment_start_dates was a continuous variable I would use
>
> -ksmirnov employment_start_date=14341+int((14705-14341+1)*runiform())

That sounds completely wrong to me: In this case your cumulative
density function contains a call to a random number generator.

> where 14705 is the first and 14341 the last day of the tax year of interest. Is this syntax line correct in case one deals with a continuous variable? If so, how can it be changed to deal with a discrete variable, which is my case?

You do so by deriving the cumulative density function for a discrete
uniform distribution and put that after the equal sign.

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/


© Copyright 1996–2014 StataCorp LP   |   Terms of use   |   Privacy   |   Contact us   |   Site index