Re: st: RE: -generate- and run time contingencies

[Richard Williams <Richard.A.Williams.5@ND.edu>]

At 11:07 AM 1/30/2006, Steichen, Thomas J. wrote:
>   . gen x = uniform()
>   . replace x = uniform() if x < 0.8
>
> accomplishes what you want.
>
> The above says replace x only if the currrent (run time) value of x 
> is less than 0.8.
>
> Tom
That was my first thought too - but it doesn't work.  The problem is 
that the replacement value may also be less than 0.8.  So, you need 
to be able to repeat the process until all x values are greater than .8.

I believe Mike's second approach would work, but only for data sets 
that are smaller than 11,000 cases (Stata SE's limit for a matrix - 
other versions of Stata have even smaller limits.)

Mike's solution of

gen x = 0.8 + 0.2*uniform()

seems to be the best for this example, but perhaps it won't always be 
so easy. (But then again, maybe it will?)

It is an interesting question - could Mata maybe handle it with large 
data sets?



-------------------------------------------
Richard Williams, Notre Dame Dept of Sociology
OFFICE: (574)631-6668, (574)631-6463
FAX:    (574)288-4373
HOME:   (574)289-5227
EMAIL:  Richard.A.Williams.5@ND.Edu
WWW (personal):    http://www.nd.edu/~rwilliam
WWW (department):    http://www.nd.edu/~soc 
*
*   For searches and help try:
*   http://www.stata.com/support/faqs/res/findit.html
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/