mf_st_numscalar.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}
{* 11feb2005}{...}
{cmd:help mata st_numscalar()}
{hline}
{* index stata scalars}{...}
{* index st_numscalar()}{...}
{* index st_strscalar()}{...}

{title:Title}

{p 4 28 2}
{bf:[M-5] st_numscalar() -- Obtain values from and put values into Stata scalars}


{title:Syntax}

{p 8 12 2}
{it:real}{bind:  }
{cmd:st_numscalar(}{it:string scalar name}{cmd:)}

{p 8 12 2}
{it:void}{bind:  } 
{cmd:st_numscalar(}{it:string scalar name}{cmd:,} 
{it:real value}{cmd:)}


{p 8 12 2}
{it:string}
{cmd:st_strscalar(}{it:string scalar name}{cmd:)}

{p 8 12 2}
{it:void}{bind:  }
{cmd:st_strscalar(}{it:string scalar name}{cmd:,} 
{it:string value}{cmd:)}


{p 4 8 2}
where

{p 8 12 2}
1.   All functions allow {it:name} to be 
{p_end}
{p 16 20 2}
     a.  global scalar such as {cmd:"myname"}
{p_end}
{p 16 20 2}
     b.  {cmd:r()} scalar such as {cmd:"r(mean)"}
{p_end}
{p 16 20 2}
     c.  {cmd:e()} scalar such as {cmd:"e(N)"}
{p_end}
{p 16 20 2}
     d.  {cmd:c()} scalar such as {cmd:"c(namelen)"}

{p 8 12 2}

{p 8 12 2}
2.  {cmd:st_numscalar(}{it:name}{cmd:)} and 
    {cmd:st_strscalar(}{it:name}{cmd:)} return a 1 {it:x} 1
    result containing the value of {it:name} or they return a 0 {it:x} 0 if
    {it:name} does not exist.

{p 8 12 2}
3.  {cmd:st_numscalar(}{it:name}{cmd:,} {it:value}{cmd:)} and 
    {cmd:st_strscalar(}{it:name}{cmd:,} {it:value}{cmd:)} allow 
    {it:value} to be
    1 {it:x} 1 containing the new value with which {it:name} is to be created
    or replaced, or 0 {it:x} 0, specifying that {it:name} is to be deleted.


{title:Description}

{p 4 4 2}
{cmd:st_numscalar(}{it:name}{cmd:)} returns the value of the specified
Stata numeric scalar, or it returns J(0,0,.) if the scalar does not exist.

{p 4 4 2}
{cmd:st_numscalar(}{it:name}{cmd:,} {it:value}{cmd:)} sets or resets the
value of the specified numeric scalar, assuming {it:value}!=J(0,0,.).
{cmd:st_numscalar(}{it:name}{cmd:,} {it:value}{cmd:)} 
deletes the specified scalar if {it:value}==J(0,0,.).
{cmd:st_numscalar("x", J(0,0,.))} erases the scalar {cmd:x}, or it does
nothing if scalar {cmd:x} did not exist.

{p 4 4 2}
{cmd:st_strscalar(}{it:name}{cmd:)} returns the value of the specified
Stata string scalar, or it returns J(0,0,"") if the scalar does not exist.

{p 4 4 2}
{cmd:st_strscalar(}{it:name}{cmd:,} {it:value}{cmd:)} sets or resets the
value of the specified scalar, assuming {it:value}!=J(0,0,"").
{cmd:st_strscalar(}{it:name}{cmd:,} {it:value}{cmd:)} 
deletes the specified scalar if {it:value}==J(0,0,"").
{cmd:st_strscalar("x", J(0,0,""))} erases the scalar {cmd:x}, or it does
nothing if scalar {cmd:x} did  not exist.

{p 4 4 2}
Concerning deletion of a scalar, it does not matter whether you code 
{cmd:st_numscalar(}{it:name}{cmd:, J(0,0,.))} 
or
{cmd:st_strscalar(}{it:name}{cmd:, J(0,0,""))}; both yield the same result.


{title:Remarks}

{p 4 4 2}
See {bf:{help mf_st_global:[M-5] st_global()}}
and
{bf:{help mf_st_rclear:[M-5] st_rclear()}}.


{title:Conformability}

{p 4 4 2}
    {cmd:st_numscalar(}{it:name}{cmd:)},
    {cmd:st_strscalar(}{it:name}{cmd:)}:
{p_end}
	     {it:name}:  1 {it:x} 1
	   {it:result}:  1 {it:x} 1  or  0 {it:x} 0

{p 4 4 2}
    {cmd:st_numscalar(}{it:name}{cmd:,} {it:value}{cmd:)},
    {cmd:st_strscalar(}{it:name}{cmd:,} {it:value}{cmd:)}:
{p_end}
	     {it:name}:  1 {it:x} 1
	    {it:value}:  1 {it:x} 1  or  0 {it:x} 0
	   {it:result}:  {it:void}


{title:Diagnostics}

{p 4 4 2}
{cmd:st_numscalar(}{it:name}{cmd:)} and 
st_strscalar(}{it:name}{cmd:)}
return J(0,0,.) (J(0,0,"")) if Stata scalar
{it:name} does not exist.  They abort with error, however, if 
the name is malformed.

{p 4 4 2}
{cmd:st_numscalar(}{it:name}{cmd:,} {it:value}{cmd:)} and
{cmd:st_strscalar(}{it:name}{cmd:,} {it:value}{cmd:)} abort with error if
the name is malformed.


{title:Source code}

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


{title:Also see}

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

{p 4 13 2}
Online:  help for 
{bf:{help mf_st_rclear:[M-5] st_rclear()}};
{bf:{help m4_stata:[M-4] stata}}
{p_end}