logit.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}
{* 07mar2005}{...}
{cmd:help logit}{right:dialog:  {bf:{dialog logit}}{space 15}}
{right:also see:  {help logit postestimation}}
{hline}

{title:Title}

{p2colset 5 18 20 2}{...}
{p2col :{hi:[R] logit} {hline 2}}Logistic regression, reporting
coefficients{p_end}
{p2colreset}{...}


{title:Syntax}

{p 8 15 2}
{opt logi:t} {depvar} [{indepvars}] {ifin} {weight} [{cmd:,} {it:options}]

{synoptset 20 tabbed}{...}
{synopthdr}
{synoptline}
{syntab :Model}
{synopt :{opt nocon:stant}}suppress constant term{p_end}
{synopt :{opth off:set(varname)}}include {it:varname} in model with coefficient
constrained to 1{p_end}
{synopt :{opt asis}}retain perfect predictor variables{p_end}

{syntab :SE/Robust}
{synopt :{opth vce(vcetype)}}{it:vcetype} may be {opt r:obust},
{opt boot:strap}, or {opt jack:knife}{p_end}
{synopt :{opt r:obust}}synonym for {cmd:vce(robust)}{p_end}
{synopt :{opth cl:uster(varname)}}adjust standard errors for intragroup
correlation{p_end}

{syntab :Reporting}
{synopt :{opt l:evel(#)}}set confidence level; default is {cmd:level(95)}{p_end}
{synopt :{opt or}}report odds ratios{p_end}

{syntab :Max options}
{synopt :{it:{help logit##maximize_options:maximize_options}}}control the maximization process; seldom used{p_end}

{p2coldent :+ {opt nocoe:f}}do not display coefficient table; seldom
used{p_end}
{synoptline}
{p2colreset}{...}
{p 4 6 2}+{opt nocoef} does not appear in the dialog box{p_end}
{p 4 6 2}{it:depvar} and {it:indepvars} may contain time-series operators; see {help tsvarlist}.{p_end}
{p 4 6 2}{cmd:bootstrap}, {cmd:by}, {cmd:jackknife}, {cmd:rolling},
{cmd:statsby}, {cmd:svy}, {cmd:stepwise}, and {cmd:xi} are allowed; see
{help prefix}.{p_end}
{p 4 6 2}{opt fweight}s, {opt iweight}s, and {opt pweight}s are allowed; see
{help weight}.{p_end}
{p 4 6 2}See {help logit postestimation} for features available after estimation.


{title:Description}

{pstd}
{cmd:logit} fits a maximum-likelihood logit model.  {it:depvar}=0
indicates a negative outcome; {it:depvar}!=0 & {it:depvar}!=. (typically
{it:depvar}=1) indicates a positive outcome.

{pstd}
Also see {helpb logistic}; {cmd:logistic} displays estimates as odds ratios.
Many users prefer the {cmd:logistic} command to {cmd:logit}.  Results 
are the same regardless of which you use{hline 2}both are the
maximum-likelihood estimator.  A number of auxiliary commands that can be run
after {cmd:logit}, {cmd:probit}, or {cmd:logistic} estimation are described in
{help logistic postestimation}.  A list of related estimation commands is
given in {help logistic estimation commands}.

{pstd}
If estimating on grouped data, see {helpb glogit}.

{pstd}
See {browse "http://www.stata.com/support/faqs/stat/rasch.html"} if
interested in the Rasch model.


{title:Options}

{dlgtab:Model}

{phang}
{opt noconstant}, {opth offset(varname)}; see {help estimation options}.

{phang}
{opt asis} forces retention of perfect predictor variables and their
associated perfectly predicted observations and may produce instabilities in
maximization; see {helpb probit}.

{dlgtab:SE/Robust}

{phang}
{opt vce(vcetype)}; see {it:{help vce_option}}.

{phang}
{opt robust}, {opth cluster(varname)}; {help estimation options}.
{opt cluster()} can be used with {opt pweight}s to produce estimates for
unstratified cluster-sampled data, but see {helpb "svy:logit"} for a command
especially designed for survey data.

{pmore}
See {helpb logistic} for examples using {opt robust} and {opt cluster()}.

{dlgtab:Reporting}

{phang}
{opt level(#)}; see {help estimation options}.

{phang}
{opt or} reports the estimated coefficients transformed to odds ratios, i.e.,
exp(b) rather than b.  Standard errors and confidence intervals are similarly
transformed.  This option affects how results are displayed, not how they are
estimated.  {opt or} may be specified at estimation or when replaying 
previously estimated results.

{marker maximize_options}{...}
{dlgtab:Max options}

{phang}
{it:maximize_options}: {opt iter:ate(#)}, [{cmdab:no:}]{opt lo:g}, {opt tr:ace},
{opt tol:erance(#)}, {opt ltol:erance(#)}; see {help maximize}.  These options
are seldom used.

{pstd}
The following option is available with {cmd:logit} but is not shown in the
dialog box:

{phang}
{opt nocoef} specifies that the coefficient table not be displayed.  This
option is sometimes used by program writers but is of no use interactively.


{title:Examples}

{phang}{cmd:. logit y x1 x2 x3}{p_end}
{phang}{cmd:. logit y x1 x2 x3, or}{p_end}
{phang}{cmd:. logit y x1 x2 x3, or robust}

{phang}{cmd:. by site: logit y x1 x2 x3}


{title:Also see}

{psee}
Manual:  {bf:[R] logit}

{psee}
Online:  {help logit postestimation};{break}
{helpb clogit}, {helpb cloglog}, {helpb glm}, {helpb glogit}, 
{helpb ivprobit}, {helpb logistic}, {helpb mlogit}, {helpb nlogit},
{helpb ologit}, {helpb probit}, {helpb roc}, {helpb scobit}, {helpb slogit},
{helpb "svy:logit"}, {helpb xtlogit}
{p_end}