mvencode.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}
{* 23feb2005}{...}
{cmd:help mvencode}, {cmd:help mvdecode} {right:dialogs:  {bf:{dialog mvencode}}  {bf:{dialog mvdecode}}}
{hline}

{title:Title}

{p2colset 5 21 23 2}{...}
{p2col :{hi:[D] mvencode} {hline 2}}Change missing values to numeric values and vice versa{p_end}
{p2colreset}{...}


{title:Syntax}

{phang}
Change missing values to numeric values

{p 8 18 2}
{cmd:mvencode} {varlist} {ifin}{cmd:,} {cmd:mv(}{it:#}|{it:mvc}{cmd:=}{it:#} [{bind:{cmd:\} {it:mvc}{cmd:=}{it:#}}...] 
[{bind:{cmd:\} {cmd:else=}{it:#}}]{cmd:)} [{opt o:verride}]

{phang}
Change numeric values to missing values

{p 8 18 2}
{cmd:mvdecode} {varlist} {ifin}{cmd:,} 
{cmd:mv(}{it:numlist} | {it:numlist}{cmd:=}{it:mvc} 
[{bind:{cmd:\} {it:numlist}{cmd:=}{it:mvc}}...]{cmd:)}

{phang}
where {it:mvc} is one of {cmd:.}|{cmd:.a}|{cmd:.b}|...|{cmd:.z}


{title:Description}

{pstd}
{cmd:mvencode} changes missing values in the specified {varlist} to numeric
values.

{pstd}
{cmd:mvdecode} changes occurrences of a {it:{help numlist}} in the specified
{varlist} to a missing-value code. 

{pstd}
Missing-value codes may be sysmiss {cmd:(.)} and the extended missing value
codes {cmd:.a}, {cmd:.b}, {cmd:...}, {cmd:.z}.

{pstd}
String variables in {varlist} are ignored.


{title:Options}

{dlgtab:Main}

{phang}
{cmd:mv(}{it:#}|{it:mvc}{cmd:=}{it:#} [{bind:{cmd:\} {it:mvc}{cmd:=}{it:#}}...] [{cmd:\} {opt else=}{it:#}]{cmd:)} is required and specifies the
numeric values to which the missing values are to be changed.

{pmore}
{opt mv(#)} specifies that all types of missing values be changed to {it:#}.

{pmore}
{opt mv(mvc=#)} specifies that occurrences of missing-value code {it:mvc} be
changed to {it:#}.  Multiple transformation rules may be specified, separated
by a backward slash {cmd:\}.  The list may be terminated by the special rule
{opt else=}{it:#}, specifying that all types of missing values not yet
transformed be set to {it:#}.

{pmore}
Examples: {cmd:mv(9)}, {cmd:mv(.=99\.a=98\.b=97)}, {cmd:mv(.=99\else=98)}

{phang}
{cmd:mv(}{it:numlist} | {it:numlist}{cmd:=}{it:mvc} [{cmd:\} {it:numlist}{cmd:=}{it:mvc}...]{cmd:)}
is required and specifies the numeric values that are to be changed to missing
values.

{pmore}
{cmd:mv(}{it:numlist}{cmd:=}{it:mvc}{cmd:)} specifies that the
values in {it:numlist} be changed into missing-value code {it:mvc}.  Multiple
transformation rules may be specified, separated by a backward slash {cmd:\}.
See {helpb numlist} for the syntax of a numlist.  

{pmore}
Examples: {cmd:mv(9)}, {cmd:mv(99=.\98=.a\97=.b)}, {cmd:mv(99=.\100/999=.a)}

{phang}
{opt override} specifies the protection provided by {cmd:mvencode} be
overridden.  Without this option, {cmd:mvencode} refuses to make the requested
change if any of the numeric values are already used in the data. 


{title:Examples}

{p 4 4 2}
    Change numeric values to missing value codes

{p 8 12 2}{cmd:. mvdecode income, mv(-1)}{p_end}
{p 8 12 2}{cmd:. mvdecode _all, mv(9999 99999)}{p_end}
{p 8 12 2}{cmd:. mvdecode religion, mv(7/9=. \ 10/15=.a)}

{p 4 4 2}
    Change missing value codes to numeric values

{p 8 12 2}{cmd:. mvencode income, mv(-1)}{p_end}
{p 8 12 2}{cmd:. mvencode _all, mv(999) override}{p_end}
{p 8 12 2}{cmd:. mvencode religion, mv(.=99 \ .a=999 \ else=9999)}{p_end}


{title:Also see}

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

{psee}
Online:  {helpb generate}, {helpb recode}