stbase.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}
{* 18mar2005}{...}
{cmd:help stbase} {right:dialog:  {bf:{dialog stbase}}}
{hline}

{title:Title}

{p2colset 5 20 22 2}{...}
{p2col :{hi:[ST] stbase} {hline 2}}Form baseline dataset{p_end}
{p2colreset}{...}


{title:Syntax}

{p 8 15 2}
{cmd:stbase} {ifin} [{cmd:,} {it:options}]

{synoptset 14 tabbed}{...}
{synopthdr}
{synoptline}
{syntab:Main}
{synopt :{opt at(#)}}convert single/multiple-record st data to cross-sectional dataset{p_end}
{synopt :{opth g:ap(newvar)}}name of variable containing gap time; default is {opt gap} or {opt gaptime}{p_end}
{synopt :{opt replace}}overwrite current data in memory{p_end}
{synopt :{opt nosh:ow}}do not show st setting information{p_end}

{p2coldent :+ {opt nopre:serve}}programmer's option; see
          {help stbase##nopreserve:Options} below{p_end}
{synoptline}
{p2colreset}{...}
{p 4 6 2}+ {opt nopreserve} is not shown in the dialog box.{p_end}
{p 4 6 2}You must {cmd:stset} your data before using {cmd:stbase}; see 
{helpb stset}.{p_end}
{p 4 6 2}Note that {opt fweight}s, {opt iweight}s, and {opt pweight}s may be 
specified using {cmd:stset}; see {helpb stset}.


{title:Description}

{pstd}
{cmd:stbase} without the {opt at()} option converts multiple-record st data
to st data with every variable set to its value at baseline, defined as the
earliest time at which each subject was observed.  {cmd:stbase} without
{opt at()} does nothing to single-record st data.

{pstd}
{cmd:stbase, at()} converts single- or multiple-record st data to a
cross-sectional dataset (not st data), recording the number of failures at the
specified time.  All variables are given their values at baseline{hline 2}the
earliest time at which each subject was observed.  In this form, single-failure
data could be analyzed by logistic regression and multiple-failure data by 
Poisson regression, for instance.

{pstd}
{cmd:stbase} can be used with single- or multiple-record or single- or 
multiple-failure st  data.


{title:Options}

{dlgtab:Main}

{phang}
{opt at(#)} changes what {cmd:stbase} does.  Without the
{opt at()} option, {cmd:stbase} produces another, related st dataset.  With
the {opt at()} option, {cmd:stbase} produces a related cross-sectional dataset.

{phang}
{opt gap(newvar)} is allowed only with {opt at()}; it specifies the name of a 
new variable to be added to the data containing the amount of 
time the subject was not at risk after entering and before {it:#} as specified
in {opt at()}.  If {opt gap()} is not specified, the new variable will be named
{opt gap} or {opt gaptime}, depending on which name does not already exist in
the data.

{phang}
{opt replace} specifies that it is okay to change the data in memory,
even though the dataset has not been saved to disk in its current form.

{phang}
{opt noshow} prevents {cmd:stbase} from showing the key st variables.  This
option is rarely used since most people type {cmd:stset, show} or 
{cmd:stset, noshow} to set once and for all whether they want to see these
variables mentioned at the top of the output of every st command; see 
{helpb stset}. 

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

{phang}
{marker nopreserve}
{opt nopreserve} is for use by programmers using {cmd:stbase} as a
subroutine.  It specifies that {cmd:stbase} not preserve the original dataset 
so that it can be restored should an error be detected or should the user 
press {hi:Break}.  Programmer's would specify this option if, in their program,
they had already preserved the original data.


{title:Examples}

{phang}{cmd:. stset failtime, failure(died) id(patid)}{p_end}
{phang}{cmd:. stcox drug bp sex}{p_end}
    {cmd:. stbase}
{phang}{cmd:. stcox drug bp sex}

{phang}{cmd:. stset failtime, f(died) id(patid)}{p_end}
{phang}{cmd:. stbase, at(5)}{p_end}
{phang}{cmd:. logistic died drug bp sex}


{title:Also see}

{psee}
Manual:  {hi:[ST] stbase}

{psee}
Online:  {help st}, {helpb stfill}, {helpb stgen},
{helpb stset}, {helpb sttocc}
{p_end}