
From  Jeph Herrin <junk@spandrel.net> 
To  statalist@hsphsun2.harvard.edu 
Subject  Re: st: file size problems 
Date  Sun, 20 Aug 2006 12:39:13 0400 
This is very helpful  guess I've been useing data for so many years, it didn't occur to me to check help use. My oversight. Thanks, Jeph Scott Merryman wrote:
Regarding the third question: rather than subset the data after it is in
memory try loading only the relevant subset,
use first.dta if month<mdy(1,1,2000)
For example:
. set memory 1m
Current memory allocation
current memory usage
settable value description (1M = 1024k)

set maxvar 5000 max. variables allowed 1.733M
set memory 1M max. data space 1.000M
set matsize 400 max. RHS vars in models 1.254M

3.987M
. sysuse auto
(1978 Automobile Data)
. expand 275
(20276 observations created)
. keep if fore ==1
no room to add more variables due to width
An attempt was made to add a variable that would have increased the
memory required to store an observation beyond what is currently possible.
You have the following alternatives:
1. Store existing variables more efficiently; see help compress.
2. Drop some variables or observations; see help drop. (Think of
Stata's data area as the area of a rectangle; Stata can trade off width and
length.)
3. Increase the amount of memory allocated to the data area using the
set memory command; see help memory.
r(902);
. save "C:\Documents and Settings\Scott_2\Desktop\temp.dta", replace
file C:\Documents and Settings\Scott_2\Desktop\temp.dta saved
. clear
. use "C:\Documents and Settings\Scott_2\Desktop\temp.dta" if fore == 1
(1978 Automobile Data)
Scott
Original Message From: ownerstatalist@hsphsun2.harvard.edu [mailto:owner statalist@hsphsun2.harvard.edu] On Behalf Of Jeph Herrin Sent: Sunday, August 20, 2006 10:50 AM To: statalist@hsphsun2.harvard.edu Subject: Re: st: file size problems Sorry, perhaps I should have been more clear. I have 3 distinct questions: 1) Why does a 500mb file require 800mb of Stata memory? 2) How to get around "op. sys. refuses to supply memory" error when using set mem 1000m in winxp (when xp should be able to access at least 2.5gb, and no other apps are running)? 3) How to drop observations once the file is in memory, when keep if mycondition gives a "no room to add more obs" error (and there is no way to increase memory)? thanks, Jeph* * 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/
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