snapspan.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}
{* 14mar2005}{...}
{cmd:help snapspan} {right:dialog:  {bf:{dialog snapspan}}}
{hline}

{title:Title}

{p2colset 5 22 24 2}{...}
{p2col :{hi:[ST] snapspan} {hline 2}}Convert snapshot data to time-span data{p_end}
{p2colreset}{...}


{title:Syntax}

{p 8 17 2}
{cmd:snapspan} {it:idvar} {it:timevar} {varlist} [{cmd:,}
	{opt g:enerate(newt0var)} {opt replace}]


{title:Description}

{pstd}
{cmd:snapspan} converts snapshot data to time-span data.  Time-span data are
required for use with survival analysis commands, such as {cmd:stcox},
{cmd:streg}, and {cmd:stset}.

{pstd}
{it:idvar} records the subject ID and may be string or numeric.

{pstd}
{it:timevar} records the time of the snapshot; it must be numeric and may
be recorded on any scale:  date, hour, minute, second, etc.

{pstd}
{it:varlist} are the "event" variables, meaning that they occur at the
instant of {it:timevar}.  {varlist} can also include retrospective
variables that are to apply to the time span ending at the time of
the current snapshot.  The other variables are assumed to be measured at the
time of the snapshot and thus apply from the time of the snapshot forward.


{title:Options}

{phang}
{opt generate(newt0var)} adds {it:newt0var} to the dataset containing the
entry time for each converted time-span record.

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


{title:Examples}

{phang}{cmd:. snapspan id time e}{p_end}
{phang}{cmd:. snapspan id time e, replace}{p_end}
{phang}{cmd:. snapspan id time e, generate(t0) replace}


{title:Also see}

{psee}
Manual:  {bf:[ST] snapspan}

{psee}
Online:  {help st}, {helpb stset}
{p_end}