Stata The Stata listserver
[Date Prev][Date Next][Thread Prev][Thread Next][Date index][Thread index]

st: Re: RE: Re: RE: Re: RE: Multiple commands under "By varlist"?


From   "Subhankar Nayak" <[email protected]>
To   <[email protected]>
Subject   st: Re: RE: Re: RE: Re: RE: Multiple commands under "By varlist"?
Date   Sat, 26 Jun 2004 11:31:16 -0400

Right. I saw your point, but I did word myself very inefficiently!

----- Original Message ----- 
From: "Nick Cox" <[email protected]>
To: <[email protected]>
Sent: Saturday, June 26, 2004 11:06 AM
Subject: st: RE: Re: RE: Re: RE: Multiple commands under "By varlist"?


> Yes and no. Sorry to repeat the point, but you 
> put the blame in the wrong place again
> in talking of the inefficiency of -while-, 
> which is just a framework and not to blame 
> for what's inside. 
> 
> The ineffiency of -while- is in going (e.g.)
> 
> local i = 1 
> while `i' < 1000 { 
> ...
> local i = `i' + 1 
> } 
> 
> rather than (say) 
> 
> forval i = 1/1000 { 
> ...
> }
> 
> -- although note that not every -while- 
> can be made a -forval- --
> 
> but that's small beer compared with the 
> possible inefficiency of what the user 
> puts within the loop, which is the issue here. 
> 
> Nick 
> [email protected] 
> 
> Subhankar Nayak
> > 
> > Yes, that's a very interesting point that I had missed.
> > I now see why -while- is so inefficient: it reads such a huge 
> > fraction of
> > unneccesary observations. I can avoid that by more efficient 
> > treatment of
> > the observation: avoid reading all those unneccesary observations
> > repeatedly.
> 
> *
> *   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/
> 

*
*   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/



© Copyright 1996–2024 StataCorp LLC   |   Terms of use   |   Privacy   |   Contact us   |   What's new   |   Site index