memory.hlp

是一个经济学管理应用软件 很难找的 但是经济学学生又必须用到

{smcl}
{* 16mar2005}{...}
{cmd:help memory}
{hline}

{title:Title}

{p2colset 5 19 21 2}{...}
{p2col :{hi:[D] memory} {hline 2}}Memory size considerations{p_end}
{p2colreset}{...}


{title:Syntax}

{p 8 13 2}
{cmd:set} {opt mem:ory} {it:#}[{opt b}|{opt k}|{opt m}|{opt g}] 
[{cmd:,} {opt perm:anently}]

{p 8 16 2}
{cmd:memory}

{p 8 15 2}
{opt q:uery} {cmd:memory}

{p 8 13 2}
{cmd:set} {opt vir:tual} {c -(}{cmd:on}|{cmd:off}{c )-}

{p 8 13 2}
{cmd: set maxvar} {it:#} [{cmd:,} {opt perm:anently}]

{phang}
where {it:#} is specified in terms of bytes, kilobytes, megabytes, or
gigabytes ({cmd:b}, {cmd:k}, {cmd:m}, and {cmd:g} may be typed in
uppercase),

{phang}
and where 2,048 {ul:<} {it:#} {ul:<} 32,767 in {cmd:set} {cmd:maxvar}.


{title:Description}

{pstd}
You can set the size of memory only if you are using
{help specialedition:Stata/SE} or Intercooled Stata.  For Small Stata, the
amount of memory used is fixed.

{pstd}
{cmd:set memory} allows you to increase or decrease the amount of memory
allocated to Stata by the operating system while Stata is running.

{pstd}
{cmd:memory} reports Stata's memory usage.  {cmd:memory} is available on all
Stata/SEs and Intercooled Statas, regardless of platform.  {cmd:query memory}
for Stata/SE reports more information.

{pstd}
{cmd:set virtual} specifies that Stata arrange data in memory to use virtual
memory more efficiently.  You do not need to {cmd:set virtual on} to use
virtual memory.  {cmd:set virtual} is {opt off} by default and is available
only in Stata/SE and Intercooled Stata.  

{pstd}
{cmd:set maxvar} allows you to set the maximum number of variables in
Stata/SE; Intercooled Stata and Small Stata do not allow you to change the
maximum number of variables.


{title:Option for memory}

{phang}
{opt permanently} specifies that, in addition to making the change right now,
the {cmd:memory} setting be remembered and become the default setting when you
invoke Stata.


{title:Option for set maxvar}

{phang}
{opt permanently} specifies that, in addition to making the change right now,
the new limit be remembered and become the default setting when you invoke
Stata.

{title:Examples}

  {title:Resetting the amount of memory}

	{cmd:. set memory 4m}
{p 8 12 2}{err:no; data in memory would be lost}{p_end}
	{search r(4):r(4);}

	{cmd:. drop _all}
	{cmd:. set memory 4m}

	{cmd:. set memory 32m}

	{cmd:. set memory 1m}

	{cmd:. set memory 1g}

	{cmd:. set memory 3g}
{p 8 12 2}{err:op sys refuses to provide memory}{p_end}
	{search r(909):r(909);}


  {title:Obtaining a memory report}

	{cmd:. memory}

    or

	{cmd:. query memory}


  {title:Using virtual memory slightly more efficiently}

	{cmd:. set virtual on}

	{it:...}

	{cmd:. set virtual off}

{p 4 4 2}
Do not {cmd:set virtual on} unnecessarily, which will slow Stata down.  Stata
goes to extra work to arrange its memory to be more efficient in using virtual
memory.


{title:Also see}

{psee}
Manual:  {bf:[D] memory}

{psee}
Online:  {helpb compress}, {helpb set matsize}, {helpb query}