{smcl}
{* 30 Jan 2002}{...}
{hline}
help for {hi:xtpattern}
{hline}


{title:Generate code showing pattern of xt data}

{p 8 12}{cmd:xtpattern} 
[{cmd:if} {it:exp}] 
{cmd:,} 
{cmdab:g:enerate}{cmd:(}{it:newvar}{cmd:)}


{title:Description} 

{p}Given a panel data set which has been {cmd:tsset} as such, {cmd:xtpattern} 
generates a string variable coding panels according to presence or 
absence of observation at different times. This variable contains 
information tabulated by {cmd:xtdes}. The same code will be assigned 
to each observation in a panel. Thus, if there were six times of observation, 
and a panel was observed at times 1, 2, 3, 4 and 6, all five observations
for that panel would be coded {cmd:"1111.1"}. 

{p}The number of observations in each panel must not exceed 80 (or under
Stata/SE, 244). 


{title:Options}

{p 0 4}{cmd:generate(}{it:newvar}{cmd:)} specifies the name of a new 
variable to hold the code. It is a required option. 


{title:Examples}

{p 4 8}{inp:. tsset id time} 

{p 4 8}{inp:. xtdes}

{p 4 8}{inp:. xtpattern, gen(pattern)}  

{p 4 8}{inp:. egen tag = tag(id)}

{p 4 8}{inp:. tab pattern if tag}


{title:Author} 

         Nicholas J. Cox, University of Durham, U.K.
         n.j.cox@durham.ac.uk


{title:Also see}

On-line: help for {help xtdes} 
 Manual: {hi:[R] xtdes}