char.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}
{* 08feb2005}{...}
{cmd:help char}
{hline}

{title:Title}

{p2colset 5 17 19 2}{...}
{p2col :{hi:[P] char} {hline 2}}Characteristics{p_end}
{p2colreset}{...}


{title:Syntax}

{p 8 25 2}{cmd:char} [{cmd:define}] {it:evarname}{cmd:[}{it:charname}{cmd:]}
[[{cmd:"}]{it:text}[{cmd:"}]]

{p 8 25 2}{cmd:char} {cmdab:l:ist}{space 5}[ {it:evarname}{cmd:[}[{it:charname}]{cmd:]} ]

{p 8 25 2}
{cmd:char} {cmdab:ren:ame}{space 3}{it:varname1 varname2}
[{cmd:,}
{cmd:replace}
]

{pstd}Also related are

{p 8 25 2}{c -(}{cmdab:loc:al} | {cmdab:gl:obal}{c )-} {it:mname} {cmd::}
{cmd:char} {it:evarname}{cmd:[}[{it:charname}]{cmd:]}

{pstd}
where {it:evarname} is a variable name or {cmd:_dta} and {it:charname} is a
characteristic name.  In the syntax diagrams, distinguish carefully between
{cmd:[]}, which you type, and [], which indicate the element is optional.


{title:Description}

{pstd}
The dataset itself and each variable within the dataset have associated
with them a set of characteristics.  Characteristics are named and referred to
as {it:varname}{cmd:[}{it:charname}{cmd:]}, where {it:varname} is the name of
a variable or {cmd:_dta}.  The characteristics contain text.  Characteristics
are stored with the dataset in the Stata-format .dta dataset, so they are
recalled whenever the dataset is loaded.

{pstd}
Characteristics are often used in Stata programs.


{title:Option}

{phang}
{cmd:replace} (for use only with {cmd:char} {cmd:rename}) specifies that if
    characteristics of the same name already exist, they are to be replaced.
    {cmd:replace} is a seldom-used, low-level, programmer's command.

{pmore}
    {cmd:char} {cmd:rename} {it:oldvar} {it:newvar} moves all characteristics
    of {it:oldvar} to {it:newvar}, leaving {it:oldvar} with none and
    {it:newvar} with all the characteristics {it:oldvar} previously had.
    {cmd:char} {cmd:rename} {it:oldvar} {it:newvar} moves the characteristics,
    but only if {it:newvar} has no characteristics with the same name.
    Otherwise, {cmd:char} {cmd:rename} produces the error message that
    {it:newvar}{cmd:[}{it:whatever}{cmd:]} already exists.


{title:Examples}

{phang}{cmd:. char _dta[one] this is char named one of _dta}{p_end}
{phang}{cmd:. char _dta[two] this is char named two of _dta}{p_end}
{phang}{cmd:. char mpg[one]  this is char named one of mpg}{p_end}
{phang}{cmd:. char mpg[two] "this is char named two of mpg"}{p_end}
{phang}{cmd:. char list}{p_end}
{phang}{cmd:. char list _dta[]}{p_end}
{phang}{cmd:. char list mpg[]}{p_end}
{phang}{cmd:. char list mpg[one]}{p_end}
{phang}{cmd:. char rename mpg weight}


{title:Also see}

{psee}
Manual:  {bf:[P] char}

{psee}
Online:  {helpb macro}, {helpb notes}; {helpb ds}
{p_end}