mf_st_rclear.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}
{* 28mar2005}{...}
{cmd:help mata st_rclear()}
{hline}
{* index st_rclear()}{...}
{* index st_eclear()}{...}
{* index st_sclear()}{...}
{* index stata r()-class results}{...}
{* index stata e()-class results}{...}
{* index stata s()-class results}{...}

{title:Title}

{p 4 4 2}
{bf:[M-5] st_rclear() -- Clear r(), e(), or s()}


{title:Syntax}

{p 8 12 2}
{it:void}
{cmd:st_rclear()}

{p 8 12 2}
{it:void}
{cmd:st_eclear()}

{p 8 12 2}
{it:void}
{cmd:st_sclear()}


{title:Description}

{p 4 4 2}
{cmd:st_rclear()} clears Stata's {cmd:r()} saved results.

{p 4 4 2}
{cmd:st_eclear()} clears Stata's {cmd:e()} saved results.

{p 4 4 2}
{cmd:st_sclear()} clears Stata's {cmd:s()} saved results.


{title:Remarks}

{p 4 4 2}
Returning results in {cmd:r()}, {cmd:e()}, or {cmd:s()} is one way 
of communicating results calculated in Mata back to Stata; 
see {bf:{help m1_ado:[M-1] ado}}.
See {bf:{help return:[R] saved results}} for a description of 
{cmd:e()}, {cmd:r()}, and {cmd:s()}.

{p 4 4 2}
Use {cmd:st_rclear()}, {cmd:st_eclear()}, or {cmd:st_sclear()}
to clear results, and then use 
{cmd:st_global()} to define macros, 
{cmd:st_numscalar()} to define scalars, 
and {cmd:st_matrix()} to define Stata matrices in {cmd:r()}, {cmd:e()}, 
or {cmd:s()}.  For example, 

	{cmd:st_rclear()}
	{cmd:st_global("r(name)", "tab")}{...}
{col 50}<- see {bf:{help mf_st_global:[M-5] st_global()}}
	{cmd:st_numscalar("r(N)", n1+n2)}{...}
{col 50}<- see {bf:{help mf_st_numscalar:[M-5] st_numscalar()}}
	{cmd:st_matrix("r(table)", X+Y)}{...}
{col 50}<- see {bf:{help mf_st_matrix:[M-5] st_matrix()}}

{p 4 4 2}
Is is not necessary to clear before saving, but it is considered good style
unless it is your intention to add to previously saved results.  

{p 4 4 2}
If a saved result already exists, {cmd:st_global()}, {cmd:st_numscalar()},
and {cmd:st_matrix()} may be used to redefine it and even to redefine it to a
different type.  For instance, continuing with our example, later in the same
code might appear

	{cmd:if (}...{cmd:) {c -(}}
		{cmd:st_matrix("r(name)", X)}
	{cmd:{c )-}}

{p 4 4 2}
Saved result {cmd:r(name)} was previously defined as a macro containing "tab",
and, even so, can now be redefined to become a matrix.

{p 4 4 2}
If you want to eliminate a particular saved result, use {cmd:st_global()}
to change its contents to "":

	{cmd:st_global("r(name)", "")}

{p 4 4 2}
Do this regardless of the type of the saved result.  Note that in this
case, we use {cmd:st_global()} to clear saved result {cmd:r(name)}, 
which might be a macro and might be a matrix.


{title:Conformability}

{p 4 4 2}
{cmd:st_rclear()}, 
{cmd:st_eclear()}, 
{cmd:st_sclear()}
take no arguments and return void.


{title:Diagnostics}

{p 4 4 2}
{cmd:st_rclear()}, 
{cmd:st_eclear()}, 
{cmd:st_sclear()}
cannot fail.


{title:Source code}

{p 4 4 2}
Functions are built-in.


{title:Also see}

{p 4 13 2}
Manual:  {hi:[M-5] st_rclear()}

{p 4 13 2}
Online:  help for 
{bf:{help mf_st_global:[M-5] st_global()}},
{bf:{help mf_st_numscalar:[M-5] st_numscalar()}},
{bf:{help mf_st_matrix:[M-5] st_matrix()}};
{bf:{help m4_stata:[M-4] stata}}
{p_end}