mf_st_varindex.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}
{* 17mar2005}{...}
{cmd:help mata st_varindex()}
{hline}
{* index st_varindex()}{...}
{* index _st_varindex()}{...}

{title:Title}

{p 4 4 2}
{bf:[M-5] st_varindex() -- Obtain variable indices from variable names}


{title:Syntax}

{p 8 12 2}
{it:real rowvector}{bind: }
{cmd:st_varindex(}{it:string rowvector s}{cmd:)}

{p 8 12 2}
{it:real rowvector}{bind: }
{cmd:st_varindex(}{it:string rowvector s}{cmd:,} 
{it:real scalar abbrev}{cmd:)}

{p 8 12 2}
{it:real rowvector}
{cmd:_st_varindex(}{it:string rowvector s}{cmd:)}

{p 8 12 2}
{it:real rowvector}
{cmd:_st_varindex(}{it:string rowvector s}{cmd:,} 
{it:real scalar abbrev}{cmd:)}


{title:Description}

{p 4 4 2}
{cmd:st_varindex(}{it:s}{cmd:)} returns the variable index associated with 
each variable name recorded in {it:s}.  {cmd:st_varindex(}{it:s}{cmd:)} does
not allow variable-name abbreviations such as "pr" for "price".

{p 4 4 2}
{cmd:st_varindex(}{it:s}{cmd:,} {it:abbrev}{cmd:)} does the same thing, but 
allows you to specify whether variable-name abbreviations are to be allowed.
Abbreviations are allowed if {it:abbrev}!=0.  
{cmd:st_varindex(}{it:s}{cmd:)} is equivalent to 
{cmd:st_varindex(}{it:s}{cmd:,} {cmd:0)}.

{p 4 4 2}
{cmd:_st_varindex()} does the same thing as  
{cmd:st_varindex()}.
The two functions differ in how they respond when a name is not found.
{cmd:st_varindex()} aborts with error, and 
{cmd:_st_varindex()} places missing in the appropriate element of the 
returned result.


{title:Remarks}

{p 4 4 2}
These functions require each element of {it:s} contain a variable name, 
such as 

		{it:s} = ("price", "mpg", "weight")

{p 4 4 2}
If you have a single string containing multiple names

		{it:s} = ("price mpg weight")

{p 4 4 2} 
then use {cmd:tokens()} to split it into the desired form, as in

		{it:k} {cmd:=} {cmd:st_varindex(tokens(}{it:s}{cmd:))}

{p 4 4 2} 
See {bf:{help mf_tokens:[M-5] tokens()}}.


{title:Conformability}

{p 4 4 2}
    {cmd:st_varindex(}{it:s}{cmd:,} {it:abbrev}{cmd:)},
    {cmd:_st_varindex(}{it:s}{cmd:,} {it:abbrev}{cmd:)}:
{p_end}
		{it:s}:  1 {it:x k}
	   {it:abbrev}:  1 {it:x} 1
	   {it:result}:  1 {it:x k}


{title:Diagnostics}

{p 4 4 2}
{cmd:st_varindex()} aborts with error if any name is not found.

{p 4 4 2}
{cmd:_st_varindex()} puts missing in the appropriate element of the
returned result for any name that is not found.


{title:Source code}

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


{title:Also see}

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

{p 4 13 2}
Online:  help for 
{bf:{help mf_st_varname:[M-5] st_varname()}},
{bf:{help mf_tokens:[M-5] tokens()}};
{bf:{help m4_stata:[M-4] stata}}
{p_end}